Will Teaching Aggressors a Lesson Deter Future Wars?

Westerners—such as NATO Secretary-General Jens Stoltenberg—who favor ever-greater levels of support for Ukraine sometimes imply that inflicting a decisive defeat on Russia will prevent future wars in other places. If Russia is decisively beaten, or at least denied any significant gains, the West will have shown that “aggression does not pay.” Not only will Russian President Vladimir Putin learn his lesson and never try something like this again, but other world leaders who might be contemplating the use of force—such as Chinese President Xi Jinping—will think twice before trying something similar.

Some observers, such as Francis Fukuyama, go even further and suggest a decisive Russian defeat could end the malaise that Western liberalism has experienced in recent years and restore the waning “spirit of 1989.”

If Ukraine and the West fail to inflict a crushing defeat on the Russian aggressor, however, and if Kyiv is eventually forced to compromise with Moscow, then illiberal ideals will be partly vindicated, and the risk of future aggression (including new Russian gambits) will increase. As U.S. President Joe Biden wrote in the New York Times: “If Russia does not pay a heavy price for its actions, it will send a message to other would-be aggressors that they too can seize territory and subjugate other countries.” More alarmingly, historian Timothy Snyder warns that “the fate of democracies hangs in the balance.”

Arguments of this sort have been a staple of hard-line (and especially neoconservative) discourse for decades. Like the domino theory, which refuses to die no matter how often it is disproved, such claims transform the outcome of a single conflict into a struggle for the fate of the entire planet. The choice we are said to face is stark. Down one path: a revitalized liberal order led by a unified alliance of powerful, peace-loving democracies, and a future where war is rare and prosperity reigns. Down the other path: a world of rising autocracy, eroding human rights, and more war. According to this view, Ukraine must win big, or all is lost.

Framing the issue in this way stacks the deck in favor of always doing more and rejecting any sort of compromise, but is the choice as stark as hard-liners make out? Does defeating an aggressor really teach others to behave better? It would be a more benign world if this were the case, but a quick glance at the past century or so suggests otherwise.

The chief aggressors were also soundly punished in World War II. Japan was firebombed repeatedly, and two of its cities were destroyed by atomic bombs; Germany was occupied and subsequently divided into two separate states; and Hitler and Italian leader Benito Mussolini both ended up dead. A clearer demonstration that “aggression does not pay” would be hard to imagine, and a good case can be made that both Germany and Japan learned that lesson well. But this lesson didn’t stop Kim Il Sung from attacking South Korea in 1950 (with Joseph Stalin’s full support) or convince various leaders elsewhere in Asia or the Middle East that going to war was always unwise.

Similarly, one might have thought the French and American experiences in Vietnam would offer a vivid and enduring reminder of the dangers of hubris and the limits of military power, not to mention the futility of trying to nation-build in a deeply divided society without a competent local partner. Yet the George W. Bush administration paid no heed to this lesson when it invaded Afghanistan in 2001 and Iraq in 2003.

Mind you, it’s not just great powers that get taught harsh lessons after launching an aggressive war. Back in 1982, Argentina’s military junta decided that the British Falkland Islands (which they call the Malvinas) were theirs and decided to take the territory by force. Britain sank the flagship of the Argentine navy and successfully retook the islands, and popular protests in Argentina eventually swept the generals from power.

Iraq’s Saddam Hussein eventually suffered a similar fate. His decision to attack revolutionary Iran in 1980 led to nearly eight years of war in which hundreds of thousands of Iraqis lost their lives and Iraq’s economy cratered. Two years later, he decided to solve the economic problems the first war had created by seizing neighboring Kuwait, only to be ignominiously expelled by a U.S.-led coalition and placed under highly intrusive United Nations sanctions. Aggression didn’t pay in either case, but Saddam’s failures didn’t stop some other countries—including some prominent democracies—from starting new wars themselves.

If painful defeats really sent clear warnings to others, the Soviet and American experiences in Afghanistan and the U.S. experience in Iraq after 2003 would have taught Putin and his associates that invading Ukraine was likely to trigger a powerful nationalist reaction and encourage outside powers to do what they could to thwart his aims. Surely he knew that the United States had helped defeat the Soviet occupation of Afghanistan by supplying the mujahideen, just as Syria and Iran had each helped the Iraqi insurgents defeat the U.S. effort in Iraq. The lesson of these two conflicts seems all too obvious, but Putin seems to have convinced himself it didn’t apply to Ukraine.

Not every aggressive war ends in defeat, of course, but there seems to be no shortage of cases where aggressors were badly beaten and more than a few where the people who started the war paid a large personal price for their folly. Yet the lesson that “aggression does not pay” is typically ignored or forgotten. Why?

One reason is that the lessons of any given war aren’t always clear-cut, and reasonable people can draw different conclusions from a defeat. Was going to war a bad idea from the start, or was defeat due to poor implementation or just bad luck? The lessons from a failed war will also be discarded if policymakers believe that this time is different, and that new knowledge, new technology, a clever new strategy, or a uniquely favorable set of political circumstances will bring success this time around. One should never underestimate what elites can talk themselves into if they really want to go to war.

Leaders may be intimately familiar with their own national histories, but they know and care less about what happened to other nations in similar circumstances.

A second problem—one highlighted in the work of the late scholar Robert Jervis—is that humans tend to place more weight on their own experiences than on the experiences of others. Leaders in one country may be intimately familiar with their own national history (though they have probably absorbed a self-serving version of it), but they will know and care less about what happened to other nations in similar circumstances.

And it’s easy to dismiss another country’s failure by claiming their cause was not as just, their resolve not as great, and their military not as competent as one’s own. Moreover, because decisions for war typically reflect a complex weighing of threats, opportunities, expected costs, and alternatives, what happened to another country in a wholly different conflict may not loom large in their calculations.

Furthermore, leaders who start wars are often aware that there are risks involved, and they sometimes recognize that the odds of victory are slim. Even so, they will “roll the iron dice” if they believe the alternative is even worse. To take an obvious example, Japan’s leaders in 1941 understood that the United States was vastly stronger and that attacking Pearl Harbor was a huge gamble that would probably fail. Nonetheless, they believed the alternative was bowing to U.S. pressure and giving up their quest for great-power status and Asian dominance—an outcome they regarded as infinitely worse.

The bottom line is that U.S. policymakers should not base their actions today on the belief that victory in Ukraine (or Yemen or Ethiopia or Libya) is going to tilt the arc of history decisively in the directions they favor. Nor will the outcome of today’s conflicts have much effect on how future leaders think about their own prospects when they are deciding whether to launch a war.

There are good reasons to support Ukraine’s efforts to resist Russia (though reasonable people can disagree about how far that support should go), but the future of democracy does not hang in the balance. Instead of seeing this war as an opportunity to teach Russia a lesson, policymakers should concentrate on identifying the specific interests and issues at stake right now and try to devise a peace settlement that can give everyone enough of what they want to discourage another round of fighting.

Figuring out how to do that is hard enough, without fooling ourselves into thinking that the fate of humanity rests on the outcome.