Arnold Kling discusses The Benefits of Hegemony — and our discomfort with hegemony:
Many liberals, of both the classical and modern varieties, are uncomfortable with hegemony. Hegemony suggests militarism and the potential for dictatorship.Some libertarians envision a government-free world, with people too dependent on trade with one another to engage in war. However, I am more sympathetic to the Hobbesian view that in the absence of government, disputes will escalate to violence.
Some liberals envision a world government, something like the European Union or the United Nations. These model governments enjoy apparently unlimited scope to make rules but ultimately no power to enforce them.
Many historians view hegemony as unstable. Inevitably, challengers arise. When they become sufficiently powerful relative to the hegemon, war breaks out. War destroys the hegemon, leading to chaos and squalid isolation.
The unpopularity of the Iraq war shows that Americans are not eager practitioners of hegemony. That is probably a good thing. However, we also should not be eager to give up hegemony. In theory, there are better alternatives. In practice, there are alternatives that are much worse.