Where elite foreign policy debates come from

In an interview with Joshua Micah Marshall, Senator Joe Biden (possible secretary of state under a Kerry administration) gives as good a summary as you'll get of the differences between the multilateral imperialism practiced by most Democrats and many 'realist' Republicans on the one hand and the unilateral imperialism of the current administration:

[I support] what I refer to as this enlightened nationalism, that we operate in our national interests in every circumstance where we can under the umbrella of international rules and the international community. But where the damage and danger is irrefutable, we reserve the right to act in our own interest or in the interest of humanity, if we have the capacity. And that is a different standard than existed for the first 27 years I was a United States senator. [sic]

That is different than the standard and the rationale of our neoconservative friends. They argue that the exercise of force is important because we are at the apex of our power and that we are more enlightened than the rest of the world. And when we have the ability to exercise force it allows us to leverage our power in direct proportion to the moral disapprobation of the rest of the world.

The two factions have a very different conception of power: the liberals see it as a scarce resource, to be carefully shepherded and used in defiance of global opinion only when all attempts at consultation and bribery have been exhausted. The neoconservatives, however, believe that power must be used to be maintained, that when we have the most power is precisely the time that it must exercised most nakedly, to eliminate any remaining challenges to American hegemony while it is best positioned to do so. And to make an example of those who still resist.

But the obligatory gestures toward the "interests of humanity" aside, both factions are seeking the same thing: permanent American supremacy in the realms of economic and military power (i.e. "national interests"). Neither side is interested in international law except to the extent it can be used to advance these goals. Both sides support parliamentary democracy, but only if the government it produces assents to American suzerainty. Both sides regularly use extreme violence, and neither side will criticize the other for doing so. The only criticisms exchanged between the two are on how effective their tactics are for advancing the shared goals.

Despite the different outlooks and occasionally fierce tactical disagreements, the two factions often function in complementary ways. A unilateral administration takes sometimes shocking steps to expand American power, increasing global resistance to American hegemony. Multilateralists are then elected who deploy soothing diplomacy, listening to alienated allies, supporting multilateral initiatives, and generally rebuilding American standing — all while consolidating the gains made under their expansionary predecessors. This is a longstanding pattern: expansion under Eisenhower, consolidation under Kennedy, expansion under Johnson, consolidation under Nixon, Ford, and Carter, expansion under Reagan, consolidation under Bush I and Clinton, expansion under Bush II...consolidation under Kerry?