Since the last realist president, George H.W. Bush, left office, two groups— neoconservatives and liberal interventionists—have overtaken American foreign policy
The United States has found itself in a seemingly endless series of wars over the past two decades. Despite frequent opposition by the party not controlling the presidency and often that of the American public, the foreign policy elite operates on a consensus that routinely leads to the use of military power to solve international crises.
Neoconservatives of both parties urge war to spread American ideals, seeing it as the duty of a great nation. Liberal interventionists see individuals, not states, as the key global actor and have deemed a Responsibility to Protect those in danger from their own governments, particularly when an international consensus to intervene can be forged. Traditional Realists, meanwhile, initially reject most interventions but are frequently drawn in by arguments that the national interest will be put at risk if the situation spirals out of control.
In a widely discussed March essay, Harvard international relations professor Stephen Walt wrote of a "neocon-liberal alliance" in support of war, contending, "The only important intellectual difference between neoconservatives and liberal interventionists is that the former have disdain for international institutions (which they see as constraints on U.S. power), and the latter see them as a useful way to legitimate American dominance."