The American foreign policy establishment prefers meddling around the globe because it can afford to without cost or political price. What is needed is a new foreign policy establishment elite based on the principles of realism and restraint.
Most realist international relations theories (and even most liberal ones) follow some fundamental assumptions—that the world is anarchic without a global policeman and global hegemony is unsustainable. Nation-states, the primary units of international politics, seek to survive in that anarchy. Of them, great powers are the main actors. States seeking hegemony are often balanced, as balancing is the norm. The system is amoral and Darwinian, and most hegemons overstretch and collapse, though some smart powers successfully retrench, or even “buck-pass” to other states during times of stress.
Different schools of realism can, of course, claim and predict different ways on whether and how states seek survival. Some would argue that states are power maximizers, while others would argue that states are overwhelmingly security maximizers. Different schools of realism also conclude different behavior even while analyzing from the same theoretical baseline. For example, all realists agree that China is the biggest potential threat to American interests. Some might argue that the United States needs to arm Taiwan and balance China actively by facilitating an alliance network in the Asia-Pacific. Others might prefer the United States to be “offshore balancers” and buck-pass the security burden to regional powers, drawing attention to the fact that China is practically alliance-less and is surrounded by powerful and rich states (most of them ideologically aligned with the United States or opposed to potential Chinese hegemony), one with nuclear power and all with large navies. The Asia-Pacific in 2021 is dissimilar to a broken Europe in 1949, susceptible to an expansionist Soviet Union.