“We are at war.” President George W. Bush used the words repeatedly after 9/11. Barack Obama used them after the San Bernardino attacks. French leaders François Hollande and Manuel Valls used them after the Paris attacks of January 2015, and again after the attacks of November. The Republican candidates for president used them in virtually every appearance they made. And the words have a certain thrill to them. One imagines the solemn delivery of declarations to foreign ambassadors, the tearful farewells as men say goodbye to their families, soldiers marching across borders and bombers taxiing on runways.

But what is a war, in the twenty-first century? If a war is what the world experienced between 1939 and 1945—a violent confrontation between sovereign states, involving the large-scale deployment of air, land and possibly sea forces by both sides in pitched battles, and the mobilization of civilians on “home fronts”—then today we live in a world without war. Indeed, the world has not seen a war, defined in this way, for many decades. The operations that the United States and its allies launched against Iraq in 1991 and 2003 came closest. But in both cases the Iraqis were so outmatched that they mostly proved incapable of taking part in serious engagements. These “wars” involved virtually no battles, if we define a battle as a sustained and intense military encounter in a well-defined area. In the entire Gulf War, fewer than 150 American personnel died. Civilian life in the United States went on without any significant civilian mobilization, except for the call-ups of reserve units in both 1991 and 2003.

In fact, the last “war” that at all resembled World War II was the Iran-Iraq War (1980–88). This conflict, like World War II, involved large-scale, sustained encounters between modern, mechanized armed forces, including tanks, artillery, airplanes and missiles. It had an identifiable front line, at least some of the time. And it ultimately cost the lives of hundreds of thousands of combatants—perhaps over a million.

But even the Iran-Iraq War was one of a relative handful of wars of this sort that have taken place since World War II. A full list would include the Korean War, the Arab-Israeli wars (up to the Yom Kippur War of 1973–4), and the Indo-Pakistani wars, but not much else. The Iran-Iraq War was far deadlier than any of these others, but even it could not begin to compare in destructiveness to World War II. Measuring battles is always a tricky business for historians, involving somewhat arbitrary distinctions (was World War I’s “Battle of the Somme,” which stretched over four and a half months, a single battle or several?), as well as wildly uncertain and disputed casualty figures. But by most commonly accepted definitions, not a single battle of the Iran-Iraq War, or any other battle fought after 1945, would come anywhere close to the top of a list of the bloodiest battles of the past century. In author Matthew White’s imaginative amateur attempt to produce such a ranking, only five battles from after 1945 figure in a list of the ninety-four bloodiest of the twentieth century, and the highest-ranking entry, the Iran-Iraq War’s Operation Karbala-5, comes in at thirty-ninth. The invention of nuclear weapons and (since the end of the Cold War) the enormous military predominance of the United States have changed the meaning of war beyond recognition.

The political scientist John Mueller, surveying evidence of this sort, has not hesitated to conclude that “war has almost ceased to exist.” He and other social scientists, most notably Steven Pinker in the 2011 The Better Angels of Our Nature, have argued that humans today have a smaller chance of dying violent deaths than at any moment in the history of the species. Terrorism, even on the scale of 9/11, has taken far fewer lives than virtually any modern war between sovereign states, and by many measures terrorism itself, despite the spectacular attacks of the past year, has itself been declining in intensity for decades.

Just as traditional definitions of war no longer fit the types of organized violence seen in the world today, in the twenty-first century sheer military power also seems to have lost much of its earlier significance. Before 1991, there was never a moment in history when one single state possessed the sort of overwhelming military advantage that the United States gained with the collapse of the Soviet Union and the end of the Cold War. Over the past twenty-five years the United States has not come close to losing this advantage. As often noted, its defense budget is as large as that of the next eight or nine largest powers combined. Its weaponry is the most advanced and powerful, its military personnel the best trained. And yet, for all this strength, the United States seems frustratingly unable to impose its will on the rest of the world. Of course, the rest of the world doesn’t see things this way, and in many senses the rest of the world is right. But there is a difference between America’s vast economic and military influence, which resonates so strongly throughout the world, and its ability to force particular recalcitrant actors into line on particular issues. President Obama was quite right to scoff at the idea that a few thousand “fighters on the back of pickup trucks” could pose an existential threat to the most powerful military force the world has ever seen. But if the mismatch is so great, why can the United States not eliminate these fighters and their pickup trucks once and for all? It is no surprise that Donald Trump’s promise to “cut the head off of ISIS and take their oil” has proven so popular with American voters.

Finally, in the twenty-first century the concept of “peace” has also lost much of its traditional conceptual salience. After 9/11, Americans widely agreed that the country was no longer at peace. Lest there be any doubt, we then staged a military invasion of Afghanistan, followed two years later by the invasion and occupation of Iraq. Did these wars ever end? Has peace returned? Today, the United States has withdrawn from Iraq, and has largely done so from Afghanistan, but there have been no celebrations of “peace.” And in Iraq and Afghanistan themselves, as in dozens of other conflict areas throughout the world, the situation can’t be easily described as either war or peace. There are no front lines, and conflict is not constant, but horrific violence nonetheless flares up, involving terrorist attacks more often than direct confrontations between armed groups.

In the United States itself, to be sure, the current situation is effectively indistinguishable from peace. Even for members of the armed forces, the odds of dying at the hands of an armed adversary or terrorist remain extremely low. But the current situation does not feel like peace to most Americans. However less violent the world as a whole has become, even with so many smoldering conflicts, the fact remains that with existing nuclear arsenals, humans still have the capacity to kill a far larger number of other humans, and do so more quickly, than at any moment in history. The risks of a nuclear exchange, or of terrorists deploying weapons of mass destruction, while presumably low, still remain almost impossible to calculate, which makes them all the more terrifying. Meanwhile, the risk of dying in a conventional terrorist attack may be low, but such attacks are spectacular, seemingly unpredictable and out of the victims’ control—much like shark attacks, plane crashes and serial killers. As with these other stalwarts of popular culture, Americans stand about as much of a chance of dying from conventional terrorism as they do of being accidentally crushed under their own furniture. But the prospect of terrorism is no easier to banish from one’s mind than the prospect of a plane crash in a plane that has just run into significant turbulence at thirty-five thousand feet.

AS AN academic, I would love to believe that we could fix our dysfunctional politics by fixing our terminology. Stop using the words “war” and “peace,” whose historical meanings have so little sense in the world in which we live today. Find new words that more precisely describe the sort of conflicts and challenges the United States faces in the world. Stop seeing these challenges through the lens of World War II, as if we could defeat ISIS with a new version of Operation Overlord, or order a massive and successful bombing attack on Iran’s nuclear program without severe consequences. Erase the word “Munich” once and for all from our political vocabularies. Remember, always, that the year is not 1938.

But no such terminological “fix” could actually achieve much in practice. The unpredictability and uncertainty of the worst challenges facing this country make them almost impossible to sum up in a catchy new word or phrase. Any such terminology would have to capture the disparity between the massive physical force that our country commands, and our inability to make use of that force, with any degree of certainty, to eliminate the scariest and most spectacular threats to our safety. In some ways, the United States today resembles a person trying to kill viruses with a hammer. It is no surprise that our media and our politicians have so little desire to acknowledge this terrifying impotence openly. Far easier to pretend we are still living in a world in which the sheer level of conventional military force is what matters, in which we could march off to a clearly defined war, win clearly defined battles and impose a clearly defined peace. Small wonder that so many Americans would prefer to pretend that the year is in fact 1938. The world of 1938 was predictable and controllable—at least in the popular imagination—in a way the world of 2016 is not. And so we can expect World War II to remain a central part of our political vocabulary long after anyone who actually remembers the conflict has died.