In 1988, the military historian James Stokesbury observed that democracies are best at fighting either little wars, which are reserved for “professionals” and don’t involve ordinary citizens, or really big wars that mobilize all of society. Those democracies, he continued, have “very real problems trying to fight a middle-sized war, where some go and some stay home.”

Middle-sized wars are big enough to cause immense destruction and bloodshed but small enough that they do not engage the full home front. They should not be confused with what the military theorist Carl von Clausewitz called a limited war, in which the goal may be only to hurt the enemy, not to destroy it. A limited war is by design, whereas a middle-sized war grows out of what was intended to be strictly a small war. Generals and political leaders know what they are doing in a limited war. U.S. leaders in today’s middle-sized wars do not.

It may be uncomfortable to consider the so-called forever wars in the Middle East—which have killed or wounded tens of thousands of U.S. soldiers and left countless dead on all sides—as merely middle-sized. But Stokesbury’s point is one of comparison. The wars in Afghanistan and Iraq, as well as those in Korea and Vietnam, as gruesome as they were, cannot be equated to the two big world wars of the twentieth century. Nor can they be grouped with little wars, such as the invasion of Grenada in 1983 and of Panama in 1989, which made headlines for a few days but were essentially imperial policing actions. U.S. military interventions in Bosnia in 1995 and Kosovo in 1999 also had exceedingly few American casualties and were mainly air operations conducted within strict limits.

For the United States, middle-sized wars present a unique problem. They ruin presidential administrations along with the American public’s regard for the U.S. government’s ability to conduct foreign policy. It would seem that the American people are finished with middle-sized wars and never want to repeat them. In fact, after each of the United States’ recent middle-sized wars, the public and politicians alike declared an end to them. This was especially true after the wars in Vietnam and Iraq, which destroyed the reputations of top policymakers. Yet the United States may be on the brink of another. The Trump administration’s war in Iran has the potential to evolve into a middle-sized war if the clerical regime does not surrender, as U.S. President Donald Trump demands, and continued U.S. and Israeli bombing leads to anarchy in Iran and destabilizes the Persian Gulf. The gap between toppling an existing order and erecting a new, more pliable one can be vast.

The United States exists in the world as a de facto empire, and misbegotten wars are embedded in the history of imperialism itself. The point of imperialism is to involve the empire in places that are potentially beneficial but not necessarily vital to its national interest. Repeated involvement in periodic middle-sized wars, even as public officials and civilians alike declare they will never happen again, reflects the modern imperial condition of the United States. If leaders are not careful, these middle-sized wars will weaken the United States and contribute to its ultimate demise.

DANGEROUS MISCALCULATIONS

In a crisis-prone world, a great power such as the United States cannot simply hide, keep a low profile, or always expect others to take action. After the invasion of Iraq, some analysts made a distinction between wars of choice and wars of necessity. But such a distinction goes only so far. Although the dichotomy certainly helps, it is not a cure-all. A war can appear to be one of necessity until it fails; then, it is looked back on as a war of choice. As Clausewitz wrote, “War is the province of uncertainty;........

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