Vinho x cerveja: qual é o melhor para a saúde?

Poucas bebidas (exceto, talvez, o chá e o café) dividem o mundo de maneira tão radical quanto a cerveja e o vinho. Gostos à parte, as duas apresentam diferença sutis na maneira como afetam o organismo e a saúde.

A BBC Future peneirou as evidências recolhidas por vários estudos científicos para tentar derrubar alguns dos mitos que cercam as duas bebidas. Sirva-se.

Qual embriaga mais rapidamente?

Uma pint de cerveja (665 ml) e uma taça média de vinho (175 ml) possuem praticamente o mesmo teor alcoólico. No entanto, a embriaguez ocorre quando esse álcool passa para a corrente sanguínea. E a velocidade com que isso acontece varia com cada bebida.

Mack Mitchell, da Faculdade de Medicina da Universidade do Texas, recentemente fez um experimento no qual pediu para um grupo de 15 homens ingerirem diferentes bebidas em dias distintos. Ele se certificou que o conteúdo alcoólico era compatível com o peso corporal de cada voluntário e monitorou para que a bebida fosse consumida no mesmo intervalo de 20 minutos.

Em um resultado pouco surpreendente, os destilados foram os que entraram na corrente sanguínea mais rapidamente. Em seguida, vem o vinho (que chega a um pico de saturação no sangue 54 minutos depois de ingerido), e a cerveja (que leva 62 minutos no mesmo processo). Em outras palavras, uma taça de vinho “sobe” mais rapidamente que uma pint de cerveja.

Conclusão: A cerveja é uma aposta mais certeira para se evitar vexames.

Why do so many Russians turn to psychics?

Large numbers of Russians are consulting mystics and psychics - up to a fifth of the population has done so at least once, according to one polling organisation. And there are signs that this tendency is increasing amid economic crisis and conflict in Ukraine.

I have never visited a psychic. So as I stand in the huge metal lift of a multi-storey building in a Moscow suburb, I am filled with curiosity, scepticism and some trepidation. My appointment is with Alexander Sheps, a celebrity psychic.

I grew up in St Petersburg, the city once home to Russia's most famous psychic, Rasputin.

But Sheps looks nothing like the bearded beady-eyed priest. Young and tall, he is rather as I would have imagined Count Dracula in his youth, but more softly spoken. His black T-shirt sports a picture of a ghostly skull.

Sheps is a winner of the The Battle of the Psychics, a reality TV show that attracts more than four million viewers per episode in Russia, even now into its 16th series.

"My main focus is communicating with the dead. I practise the art of magic,

I practise ritual magic, spells. I can search for people who have disappeared," he tells me.

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Media captionWatch Alexander Sheps, one of Russia's best-known psychics, at work

Opinion polls by the independent Levada Centre estimate that a fifth of Russians have visited a psychic. Another polling organisation, Sreda, estimated in 2013 that 63% believe in either astrology, fortune telling or the concept of the evil eye.

From what Sheps says, it seems that there is a particular demand for his services among the urban middle class.

"There are bankers, there are very famous politicians, a lot of famous people. My clients include two Orthodox priests. Despite praying in the church and having a congregation, they come to me to solve their problems," he says.

Image captionOrthodoxy and the occult are as compatible as mustard and ice cream, says Andrei Kuraev

Psychics and the occult are officially anathema to the Orthodox Church, but deacon Andrei Kuraev, who has spent the last 25 years discrediting psychics, say it's not that surprising that some believers put their faith in charlatans.

"You can be Orthodox and a murderer, you can be Orthodox and a burglar," he says. "No-one can force a person to be logical. That's why completely incompatible ingredients co-exist in people's heads, like ice-cream with mustard."

Christianity in Russia can be traced back over a millennium, but pagan beliefs never entirely disappeared in rural areas. Some believe this, and the existence of Shamanistic and other non-Christian beliefs in the country's vast eastern regions, could help explain the continuing appeal of the occult.

Even the USSR's militant atheism failed to suppress popular curiosity.

I remember that in the 1970s and 80s Russian intellectuals, sometimes with doctorates in science, searched for alternatives to so called "scientific socialism" - even though an interest such things could lead to imprisonment or compulsory psychiatric treatment.

At the same time, however, the Soviet authorities secretly tried to harness the powers of psychics to locate enemy nuclear submarines, or to "read" secret documents locked inside safes in Western capitals.

It's no surprise, then, that in today's Russia some people in pretty responsible positions are resorting to psychics.

Detective Dmitry Bykov was recently investigating a particularly gruesome murder. The victim was incinerated in a car, and there were no clues, so a psychic was summoned to the scene of the crime.

Image captionDmitry Bykov asked a psychic to help while investigating a particularly difficult murder case

"She had evidently connected with some flow of information… she told us to go somewhere, so we left," Bykov says.

"She said that it was as if she was being pulled by some sort of rope straight to that place. On the way she gave us information, such as who was killed, where, and the description of the person, his appearance, his lifestyle, whom he had been hanging out with.

"Bit by bit a picture began to emerge."

Nothing the psychic says can be used in court, though. Any "leads" provided have to be investigated in the usual way - and Bykov didn't tell me how useful they turned out to be in this case.

The woman he and his colleagues consulted was 31-year-old Galiya Galieva, whose main speciality is numerology - the belief in a mystical relationship between numbers and events - and, rather surprisingly, personnel issues.

Image captionGaliya Galieva's speciality is numerology

"I have consulted the psychic many times about hiring staff," says Valeria Pervitskaya, another of Galieva's clients, who runs a business making ready meals.

"She examined their photographs and birth dates, and told me whom to employ. This helped me to build the right team.

"It is a great advantage if you know whom to employ, who does not suit you, if someone would steal from you," she says, her carefully selected staff busily chopping vegetables in the background.

Image captionValeria Pervitskaya with some of her team

Psychotherapist Dmitry Olshansky links the growing popularity of psychics to Russia's economic crisis - since last December the value of the rouble has halved.

"People feel unsure. And they want to rely on somebody. They need a 'parent' figure, a shoulder, or somebody who would tell them how to live and what to do," he says.

"Moreover, Russians don't have reliable sources of information. What people see on television, what they read in newspapers does not correspond to reality. And they know this."

This, he suggests, increases their need for someone who appears to have special powers to discern the truth.

A chemistry teacher's guide to the perfect cup of coffee

Sometimes you just want a caffeine hit to wake you up, but if you appreciate the finer points of a cup of coffee, it’s worth going right down to the chemistry of the water, milk, sugar – and salt

As a chemistry teacher, I’m inevitably fascinated by chemistry in general, but especially by the chemistry we come across on a daily basis. Rather than only sharing this with my students, I started a website, Compound Interest, where I create illustrated explanations of chemical concepts for anyone who’s interested to gain a better insight into the chemistry that pervades our lives.

So what can chemistry do for you? Well, for starters, it can help you make a better cup of coffee.

Any coffee connoisseur will tell you that good coffee should never taste bitter. However, in the less-than-ideal coffee world that the majority of us inhabit, bad, bitter-tasting coffee is much more common than we’d like. Luckily, there are plenty of tips out there on how to improve this, including the odd-sounding suggestions that adding a pinch of salt to coffee can improve the flavour. Science can help us explain how these suggestions might work – and how to make the perfect cup of coffee.

What makes coffee taste bitter?

Surprisingly, we still don’t know exactly what it is that makes some coffee taste bitter. Although the caffeine that’s present has a mildly bitter taste, it isn’t the main bitter component. Compounds called chlorogenic acid lactones and phenylindanes are thought to contribute; the former are in high levels in light- to medium-roast coffee, whereas the latter are found in darker roasts, and have a harsher taste.

Does adding salt to coffee temper bitterness?

Adding a pinch of salt might seem an unusual way to counter bitterness, but the science checks out. Researchers back in 1997 put it to the test by mixing salt into solutions of a bitter-tasting chemical and getting subjects to judge the bitterness. The volunteers consistently rated the solutions containing salt as being less bitter, despite the fact that the concentration of the bitter chemical in both solutions was identical.

The coffee-water balance

Remedying bad coffee-making with salt is a solution of sorts, but it’s better to tackle the problem closer to the cause. Extraction is a precise chemical process that can be tweaked in order to improve the flavour of your coffee. One important aspect is the ratio of coffee to water during the brewing process. Around 60g of coffee to a litre of water is recommended; in slightly more useful terms, that works out as a single gram of coffee for every 16ml of water, or around 7g for a single espresso shot.

The coffee-water balance is important because too much coffee can lead to greater extraction of bitter compounds, as the water is in contact with the coffee for longer. On the other hand, too much water will lead to a dilute, weak-tasting coffee.

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 Photograph: Edmund D. Fountain/ZUMA Press/Corbis

Brewing time and bitterness

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Brewing time is another important factor. At a simple level, there are three stages of compounds extracted from coffee. Acidic, fruity-flavoured compounds are the first to be extracted, followed by more earthy, caramel-like compounds, and finally the bitter-tasting compounds. Short brew times lead to only the first group of compounds being extracted, whereas over-brewing can lead to an excess of the bitter, astringent flavours.

For the best coffee, we have to aim between these two extremes. Different coffees come with different recommendations. For an espresso coffee, the water should only be in contact with the coffee for 20-30 seconds; in a plunger pot, this increases to 2-4 minutes.

Temperature and bitterness

Water temperature also affects the bitterness. The ideal temperature is between 91-96˚C – higher than this, and you’re likely to burn the coffee, increasing the concentration of astringent compounds. Lower temperatures lead to poor overall extraction of compounds from the coffee. Conversely, the much lower temperature of cold-brew coffee does lead to lower dissolved levels of the compounds causing bitterness, though it comes with the trade-off of a much-elongated brewing time.

Type of coffee and grinding

Even the best extraction technique in the world can be thwarted by poor-quality coffee. There are two primary types, arabica and robusta, with arabica widely considered to have the finer flavour. Robusta coffee contains higher concentrations of phenols, pyrroles, and sulfur compounds, leading to a flavour unflatteringly described as harsh and rubbery.

The size of the particles in your coffee grounds can also help or hinder. Too large, and the compounds will be extracted ineffectively, leading to weak-tasting coffee. Too fine, and the compounds, including the bitter-tasting ones, will be extracted too quickly. Again, it’s the case of finding that perfect balance.

Milk, sugar and coffee

If the honing of your extraction method fails miserably, you can always remedy your bitter coffee in a more traditional manner. Milk simply masks the taste, but it also contains the sugar lactose which can impart a degree of sweetness. Sugar, on the other hand, causes caffeine molecules to clump together, which along with its taste-masking ability helps to reduce the perception of bitterness.

It’s clear that a good cup of coffee is harder to create than you might have expected. Still, there are bound to be times when the quality of the coffee isn’t of primary importance – I know that, as a teacher, starting the day at six in the morning, I’m more concerned with getting the caffeine hit than I am with the finer points of coffee flavour. Nonetheless, equipped with the knowledge of the science behind the extraction process, a better morning coffee is within your grasp.

Why the U.S. may still have to go to war against Iran

Effective enforcement of the Iranian nuclear deal remains a conundrum. Enshrined in the agreement is “snapback” – the restoration of international economic sanctions against Tehran should it violate the deal’s terms. Yet the expected rush of European, Russian and Chinese businesses into Iran would make such unified action questionable.

Aware that economic pressure might not be enough, U.S. officials have repeatedly declared “all options” are on the table. Though most have been reluctant to offer details, recent Pentagon talk has focused on a new bunker-buster bomb. Such talk feeds into the growing presumption that Washington would rely on air strikes if Iran violated the agreement.

Iran’s Supreme Leader Ayatollah Ali Khamenei waves to the crowd in the holy city of Qom, 120 km (75 miles) south of Tehran, October 19, 2010. REUTERS/Khamenei.ir

Yet history shows that forceful alternatives either don’t work or are too dangerous and costly. In addition, past air strikes have proved to be unreliable. So policymakers should indeed consider all options. Previous tactics — including assassination, special-forces sabotage, technology disruption, armed forces mobiliztion, massive bombing and war — deserve another look.

Some tacks have worked better than others. Determining the best course, however, can be complicated. Here’s a list:

1)  Assassination marks the nadir on the violence spectrum. It has reportedly been applied by Israel against Iraqi and Iranian scientists — for example, the bomb, delivered by motor cycle, that struck the car in Tehran in which Majid Shahriari, a senior nuclear engineer, was riding in 2010. But the tactic has failed to seriously hinder nuclear development.

Vemork Hydroelectric Plant in Rjukan, Norway in 1935. A commando team blew up heavy water production cells in 1943 to sabotage Nazi German’s nuclear energy project. WIKIPEDIA

2) Sabotage by special forces of nuclear installations has had more impact but is not enduring. One early application was during World War Two, when British commandos attempted to destroy a plant in Nazi-occupied Norway that produced heavy water, a vital substance Germany required for the nuclear weapons effort. Israel’s 1979 commando detonation of the Osirak reactor core as it sat in a French warehouse awaiting shipment to Iraq marks a second case. In both instances, engineers repaired the damaged equipment within months.

3) Sabotage of a different sort, including cyberattacks on Iran’s uranium- enrichment plants, as well as the adulteration of material imported to fabricate centrifuges, set back Tehran’s nuclear program by months. But that was it.

4) Air strikes. Without the precise delivery systems of current air forces, the United States tried a massive bombing campaign during World War Two to destroy the Norwegian heavy-water plant after Britain’s attempted sabotage failed. Even with that, the allies needed a follow-up commando operation to eliminate the surviving heavy-water stocks. But the success in Norway failed to halt Nazi Germany’s program back in Germany. Scientific barriers proved far more important in undermining the Nazi effort.

Before and after photos of the Syrian reactor site released by the U.S. government after the Israeli attack in 2007. Wikipedia/commons

With more advanced aircraft, Israel’s bombardment of Iraq’s Osirak reactor in 1981, and Syria’s Al Kibar reactor in 2007, succeeded far more efficiently. The destruction of Syria’s reactor may be the most effective use of force in history. With few resources to rebuild the North Korean-engineered plant, Damascus abandoned its nuclear effort.

The attack on Iraq’s Osirak reactor told another story. Here, destruction prompted Baghdad to undertake a 10-year covert effort to enrich uranium. By some estimates, Iraq was within a year of succeeding when the 1991 Persian Gulf War broke out.  

But bombing will not prevent efforts at covert reconstruction by countries with the personnel, drive, resources and effective stealth to do the job. Iran, unlike Syria, falls into this category.

5) War or the threat of war. In the end, the only forceful policy that eliminated emerging nuclear weapons programs with certainty — putting aside voluntary monitored relinquishment by former Soviet states, South Africa and Libya — was the successful wars waged against Nazi Germany in World War Two and Iraq in 1991. Occupying military forces in the first case, and international inspectors in the second, were able to eliminate all nuclear contraband.

War, however, remains the most costly option, in both blood and treasure.

It also adds a wrinkle, not in its application, but in its gestation. The Cuban missile crisis demonstrated that threat manipulation — preparations for the use of overwhelming military force to invade the island, coupled with the naval quarantine and the ramping up of the alert status of the nuclear arsenal — intimidated Moscow to abandon its Cuba gambit.

But coercive diplomacy is never a sure thing. Think about the massive buildups undertaken by U.S. and allied forces against Iraq in 1991 and 2003. Both failed to intimidate, and war ensued.

6) There is one last option of the “all options” alternative that policymakers appear loath to talk about: acceptance of Iran as a nuclear armed state. Farfetched? Even the Israelis apparently gave a nod to that possibility when Ehud Barak, former prime minister and defense minister, recently revealed that, between 2010 and 2012, Jerusalem seriously contemplated military action against Iran but then got cold feet.

For Washington to take this course would actually be consistent with historic behavior. When faced with a nuclear buildup in China during the early 1960s, North Korea in recent years and the Soviet Union at the beginning of the Cold War, the United States decided that managing an adversary with an emerging nuclear arsenal was a better course than using force to stop it. Of course, acceptance of Iran into the nuclear club banks that it will be a responsible steward of the bomb.

History’s lessons for halting Iran’s nuclear temptation are sobering. “All options are on the table” may be a nice catch phrase — but if the mullahs attempt a nuclear breakout, only a winning war would guarantee full success.

Half measures, notably air strikes, may buy time to sway Tehran to rethink its nuclear course. But the past’s inconvenient truth remains: Unless Iran complies with the recent agreement and the underlying nuclear Non-Proliferation Treaty, Washington faces a daunting choice should snapback fail. It can go to war or bet that deterrence applied against nuclear adversaries in the past will work again against Iran’s revolutionary regime.

rocessed meats rank alongside smoking as cancer causes -

Bacon, ham and sausages rank alongside cigarettes as a major cause of cancer, the World Health Organisation has said, placing cured and processed meats in the same category as asbestos, alcohol, arsenic and tobacco.

The report from the WHO’s cancer arm, the International Agency for Research on Cancer, said there is enough evidence to rank processed meats as group 1 carcinogens, because of a causal link with bowel cancer.

It places red meat in group 2A, as “probably carcinogenic to humans”. Eating red meat is also linked to pancreatic and prostate cancer, the IARC says.

The IARC’s experts concluded that each 50 gram portion of processed meat eaten daily increased the risk of colorectal cancer by 18%.

“For an individual, the risk of developing colorectal cancer because of their consumption of processed meat remains small, but this risk increases with the amount of meat consumed,” said Dr Kurt Straif, head of the IARC monographs programme. “In view of the large number of people who consume processed meat, the global impact on cancer incidence is of public health importance.”

The decision from the IARC, after a year of deliberations by international scientists, will be welcomed by cancer researchers but it triggered an immediate and furious response from the industry, and the scientists it funds, who rejected any comparison between cigarettes and meat.

“What we do know is that avoiding red meat in the diet is not a protective strategy against cancer,” said Robert Pickard, a member of the Meat Advisory Panel and emeritus professor of neurobiology at the University of Cardiff. “The top priorities for cancer prevention remain smoking cessation, maintenance of normal body weight and avoidance of high alcohol intakes.”.

But the writing has been on the wall for ham, bacon and sausages for several years. The World Cancer Research Fund has long been advising people that processed meat is a cancer hazard. It advises eating products such as ham, bacon and salami as little as possible and having no more than 500g a week of red meat, including beef, pork and lamb.

Prof Tim Key, Cancer Research UK’s epidemiologist at the University of Oxford, said: “Cancer Research UK supports IARC’s decision that there’s strong enough evidence to classify processed meat as a cause of cancer, and red meat as a probable cause of cancer.

“We’ve known for some time about the probable link between red and processed meat and bowel cancer, which is backed by substantial evidence.

“This decision doesn’t mean you need to stop eating any red and processed meat. But if you eat lots of it you may want to think about cutting down. You could try having fish for your dinner rather than sausages, or choosing to have a bean salad for lunch over a BLT.”

The statement from the IARC, published as an article in the journal Lancet Oncology, substantially toughens the line, especially against processed meat. But while cancer scientists are concerned about the risks of eating too much meat, some nutritionists maintain that the extra risk is relatively small and that meat has other benefits.

Dr Elizabeth Lund – an independent consultant in nutritional and gastrointestinal health and a former research leader at the Institute of Food Research, who acknowledges she did some work for the meat industry in 2010 – said red meat was linked to about three extra cases of bowel cancer per 100,000 adults in developed countries.

“A much bigger risk factor is obesity and lack of exercise,” she said. “Overall, I feel that eating meat once a day combined with plenty of fruit, vegetables and cereal fibre, plus exercise and weight control, will allow for a low risk of colorectal cancer and a more balanced diet.”

Prof Ian Johnson, emeritus fellow at the Institute of Food Research, also said the effect was small. “It is certainly very inappropriate to suggest that any adverse effect of bacon and sausages on the risk of bowel cancer is comparable to the dangers of tobacco smoke, which is loaded with known chemical carcinogens and increases the risk of lung cancer in cigarette smokers by around twentyfold.”

The North American Meat Institute said defining red meat as a cancer hazard defied common sense.

“It was clear, sitting in the IARC meeting, that many of the panellists were aiming for a specific result despite old, weak, inconsistent, self-reported intake data,” said Betsy Booren, the institute’s vice-president of scientific affairs. “They tortured the data to ensure a specific outcome.

“Red and processed meat are among 940 agents reviewed by the IARC and found to pose some level of theoretical ‘hazard’. Only one substance, a chemical in yoga pants, has been declared by the IARC not to cause cancer.

“The IARC says you can enjoy your yoga class, but don’t breathe air (class 1 carcinogen), sit near a sun-filled window (class 1), apply aloe vera (class 2B) if you get a sunburn, drink wine or coffee (class 1 and class 2B), or eat grilled food (class 2A). And if you are a hairdresser or do shift work (both class 2A), you should seek a new career.”

A $550 million Air Force bomber so good it will never be used

The Air Force wants a new bomber so that it never actually has to use it.

The Defense Department recently announced it will soon pick a contractor to build a new stealth bomber for the Air Force. The potentially $80-billion Long-Range Strike Program is a big deal, particularly for the Air Force. It hasn’t developed a new bomber in more than 30 years. The Pentagon is increasingly worried that its existing fleet of about 160 B-52s, B-1s and B-2s is largely outdated, vulnerable to the newest Chinese- and Russian-made air defenses.

The Air Force wants up to 100 new bombers armed with all the latest weaponry and radar-evading stealth technology — and plenty of fuel. For the new warplanes must be able to fly long distances, penetrate even the heaviest defenses and destroy scores of targets in a single bombing run.

That doesn’t mean, however, that the Pentagon really believes it will be fighting a war against Russia or China. Defense planners instead want the new bombers to reinvigorate a once-key concept that the military has allowed to atrophy: conventional deterrence.

By deploying high-tech armaments of such fearsome nonnuclear destructive power, the mere presence of such weapons should give pause to U.S. enemies. This would buy time so diplomats could negotiate to work out major conflicts without anyone resorting to violence.

Bomber genesis

The new bomber has been a long time in the making. As early as 2004, Air Force planners began talking about buying new heavy warplanes and introducing them into service as early as 2018. The planes would partly replace B-52s, which were built in the 1960s, B-1s, which date to the 1980s, and 1990s-vintage B-2s.

Still of B-52 bomber in “Dr. Strangelove.” Courtesy of Columbia Pictures.

But in 2010, then-Defense Secretary Robert Gates put the bomber effort on hold; he cited the Air Force’s tendency to develop overly complex and expensive warplanes. The flying branch had intended to buy 132 of the radar-evading B-2s. But the stratospheric costs and post-Cold War budget cuts made that goal unrealistic. The Air Force ended up getting just 21 B-2s, at a price of more than $2 billion a plane, including research and development costs.

The Pentagon allowed the Air Force to restart bomber development in 2011, but with a firm cap on the costs. Each of the up to 100 new bombers could cost no more than $550 million, or roughly $800 million, including research and development. Northrop Grumman, which built the B-2, is competing against a consortium of Boeing and Lockheed Martin for the contract, which should be awarded later this year.

The Air Force is aiming for the new bombers to be on air base ramps by the mid-2020s — just a decade after the signing of the contract. This in an era when major warplane programs can take 20 years or more from contract to fielding.

“We have to build affordability, right from the beginning, into our new programs, whenever we have the opportunity to do so,” Air Force Secretary Deborah Lee James said in a 2014 press conference, “… [T]hat’s what we did with the Long-Range Strike Bomber.”

The relatively low cost and quick deployment timeline are feasible because the Air Force is urging the industry teams to include as much existing, or “mature,” technology as possible in their designs — rather than reinventing everything from scratch, as is often the case. One unnamed official told Aaron Mehta of Defense News that the new bomber has the “highest level of maturity” he’d ever seen in a warplane program.

This newfound discipline reflects the Pentagon’s serious interest in acquiring new bombers. The military has come to believe that new bombers will play a crucial role in preventing full-scale war between the major powers.

Peace through strength

That wasn’t always the case.

In the early 2000s, the Defense Department had proposed to wait until 2037 for a new bomber. That made sense at the time. Russia was still suffering economic hardship and political dysfunction. Moscow had yet to begin asserting itself militarily as it has since in Georgia, Ukraine, Syria and other countries along its periphery.

China’s economic and military expansion was then just beginning. Beijing was still years away from making forceful claims in the China Seas.

One of three Air Force Global Strike Command B-2 Spirit bombers returns to home base at Whiteman Air Force Base in Missouri, March 20, 2011. REUTERS/Kenny Holston/U.S. Air Force photo/Handout

Meanwhile, the United States was fighting major counterinsurgency campaigns in Iraq and Afghanistan against low-tech foes who had no means of shooting down high-flying bombers. The Air Force’s B-2s, B-1s and B-52s were able to fly missions over Iraq and Afghanistan without crews having to worry much about enemy defenses. There was no compelling need for a high-tech new bomber — as long as the older bombers were still perfectly adequate for the wars at hand.

Today, U.S. military strategy — and the world’s — has changed. The U.S. occupation of Iraq has concluded; the West’s coalition in Afghanistan ended its frontline ground-combat mission in late 2014. U.S. warplanes, including B-1s, are waging an intensive air campaign against Islamic State militants in Iraq and Syria. But in July, the Air Force secretary said a resurgent Russia was the biggest threat to U.S. national security, a sentiment that Marine Corps General Joseph Dunford, the new chairman of the Joint Chiefs of Staff, echoed the same month.

The Pentagon is developing the Long Range Strike Bomber with this new threat assessment in mind. “We need to get ahead of the curve when it comes to the enormous and very rapid change that we’re seeing in our world,” James said in her press conference last year. “We have to maintain that technological edge.”

Russia produces the best surface-to-air missile systems in the world, and China’s missiles are nearly as good. To pose any substantive opposition to Russian and Chinese forces, the Long Range Strike Bomber needs to be able to penetrate these defenses by avoiding detection. The new bomber is intended to be stealthier than the famously elusive B-2, sources told Defense News. The B-2′s “flying wing” shape and special surface coating are designed to scatter some radar waves and absorb others, helping minimize the plane’s “signature” on enemy radar scopes.

But for all this effort in tailoring the Long Range Strike Bomber to defeat Russian and Chinese defenses, the Pentagon still hopes the new warplane will never drop a bomb on either one. They instead talk about it as having a stabilizing effect.

Crisis stability

The Air Force has good reason to subscribe to this theory, as counterintuitive as it might sound. In 2013, the aviation branch commissioned Forrest E. Morgan, an analyst at the RAND Corporation, a California policy organization, to determine how well certain military forces could stabilize an escalating international crisis without ever firing a shot.

“Crisis stability and the means of achieving and maintaining it — crisis management — are not about warfighting,” Morgan wrote. “They are about building and posturing forces in ways that allow a state, if confronted, to avoid war without backing down.”

President John F. Kennedy with Defense Secretary Robert S. McNamara (R) at the National Security Council Executive Committee meeting in the White House Cabinet Room, October 29, 1962. John F. Kennedy Presidential Library and Museum/Cecil Stoughton

The Cuban missile crisis is one prominent, if imperfect, example that Morgan analyzed in his study. In response to the U.S. nuclear buildup in Europe, the Soviet Union, in 1962, began building missile sites in Cuba. President John F. Kennedy deployed U.S. forces around Cuba, and the Soviets backed down — after Kennedy agreed to dismantle some U.S. nuclear missiles in Europe.

Military shows of force around Cuba, if at times risky and clumsy, positioned both the United States and the Soviet Union to be able to reach a peaceful settlement without either side suffering humiliation.

The United States and other countries took the same approach to major potential conflicts throughout the 20th century. But crisis-management practices fell out of favor following the Soviet Union’s collapse in 1991.

Morgan’s study urges a revival. “The reemergence of great-power competitors,” he warned, “will make dangerous interstate confrontations increasingly likely in the future.” Morgan examined other historical examples and compared how the deployment of different weapons — bombers, fighter jets and missile-armed submarines — helped ease tensions by making actual combat unthinkably costly. Sometimes, however, it also worsened them, by surprising the enemy and forcing a panicky reaction.

“Stability requires forces that are powerful enough to deter a potential enemy,” Morgan wrote, “but employable in ways that minimize their exposure to surprise attack.”

Morgan’s conclusion is unequivocal. Fighter jets, capable of flying only short distances, must deploy so close to the enemy that they could attack — and be attacked – quickly. This makes a destabilizing surprise attack dangerously tempting for what Morgan calls a “risk-tolerant” country.

Submarines, because they are underwater most of the time and thus invisible, can prove even more surprising — and thus destabilizing. What’s more, a submarine can’t “signal,” to borrow Morgan’s term. Signaling is when a country deliberately but carefully deploys highly visible forces as a statement to its enemy that doesn’t want to go to war — but could if diplomacy fails.

Long-range bombers deployed far from enemy shores are the most stabilizing weaponry, in Morgan’s assessment. “Bombers generate a potent deterrent threat,” he wrote, “without exposing U.S. forces to an inordinate amount of vulnerability to surprise attack.”

But there’s a catch here. To back up their threat, the bombers must actually be capable of penetrating enemy defenses — and that disqualifies older models, according to Morgan. To keep the peace between major powers, the Air Force needs a high-tech new bomber that, ironically, is fully capable of wreaking havoc on U.S. enemies.

If this all works as expected, in coming months the Pentagon will tap a contractor to build the Long Range Strike Bomber. A decade later, those bombers will be available to deploy in crises pitting the United States against a fellow world power. Then, if all goes according to plan, the fearsome new bombers will never, ever drop a single bomb.