Like it or not, America’s failure in Iraq does not change the fact that global stability depends on American global leadership, and American global leadership costs money. The United States is at the heart of a dense web of alliances. We extend formal security guarantees to more than 50 countries. Some see these alliances and guarantees as little more than a burden the U.S. can no longer afford. Yet what they actually do is dampen security competition. They reassure partner countries that they needn’t build up their militaries to defend themselves against their neighbors, which then reassures their neighbors that they needn’t build up their militaries. This virtuous cycle is one of the central reasons Western Europe and Japan recovered so quickly after the devastation of World War II, and why globalization has helped ease poverty around the world. For this virtuous cycle to be maintained, however, U.S. security guarantees must be considered credible. It must be clear that when the U.S. makes a security commitment to another country, that commitment will be met. This in turn means that the U.S. military must have the power and the reach to defend countries far from our borders…

The neocon impulse proved badly misguided in Iraq, where it contributed to a moral calamity. But there are other cases, in South Asia in 1971 and in Bosnia in the early 1990s, to name two examples among many, where it might very well have prevented one.