Kenneth Waltz famously claimed that states are "functionally undifferentiated" and that the internal characteristics of states (e.g. the type of regime) are irrelevant for understanding state behaviors. In other words, states act according to capabilities rather than characteristics, and so all states may be viewed as unified entities seeking roughly the same goals.
This realist view of the states as undifferentiated unitary actors has come under fire from many quarters, and with good reason. Empirical evidence shows that internal characteristics of states can have large effects on their foreign relations. For example, democratic states do not fight each other (but fight non-democratic states with gusto). Internal characteristics of states can make signals more or less credible, can give national leaders more or fewer tools for statecraft, can limit or expand the range of foreign policies from which leaders may choose, and otherwise differentiate the behavior of states in a number of ways. Still, Waltz's idea travels far enough to be helpful for understanding many international interactions.
Take the formation of Obama's policy towards Iran, for example, as Roger Cohen does in an extensive article in the NY Times Magazine:
“Who [Iranians] select as leader is their prerogative, and there’s nothing we can do to control that,” Ray Takeyh, an Iranian-born adviser to Dennis Ross, the veteran Mideast negotiator who has been working on Iran for the Obama administration, told me before the election. “We’re trying to deal with Iran as an entity, a state, rather than privileging one faction or another. We want to inject a degree of rationality into this relationship, reduce it to two nations with some differences and some common interests — get beyond the incendiary rhetoric.” Takeyh’s words reminded me of Ross, who in his book “Statecraft” defined the term’s first principles as, “Have clear objectives, tailor them to fit reality.”
This comes as something of a departure from previous administrations, and other factions within the American government and even Obama's own State Department. President Bush preferred to see things in more moralistic terms (democracy = good; authoritarianism = Axis of Evil), while Senator McCain -- Obama's rival for the presidency -- famously proposed a "League of Democracies" to police the globe. Secretary of State Clinton -- perhaps inspired by her husband's belief in the necessity of humanitarian interventions -- preferred taking a stronger line against Tehran after the crackdown on protestors following the recent disputed Iranian election, and Vice President Biden agreed with her. But Obama, taking a page from Kissinger's realpolitick, clearly prefers rapprochement to rhetoric.
Still, the rest of Cohen's article is thick with individual personalities, philosophies, and strategies that are vying for influence in the American, Israeli, Russian, Chinese, Saudi Arabian, and Iranian administrations. As some approaches win out over others, the foreign policies of states shift; and as policies shift, so do outcomes. So perhaps we can score one for the argument that just as capabilities matter, so do interests, identities, and institutions at the national level.
Finally, as an aside, what in the hell does this mean?
Indeed, what looms for the Obama administration is a core test, over Iran, of its new foreign-policy doctrine. This was defined by Hillary Clinton as follows: “We will lead by inducing greater cooperation among a greater number of actors and reducing competition, tilting the balance away from a multipolar world and toward a multipartner world."
Whatever that is, it isn't realist.
ADDENDUM: Drezner sees less realism in Obama's foreign policy, or at least fewer realistic hopes for that approach. But when I read the passages he cites (about Ross' humiliating meeting with King Abdullah), I got the impression that Ross was simply unprepared for the questions Abdullah asked. This may be more a function of the fact that the administration had been in office for a mere 99 days when Ross took that meeting (apparently the Saudi King doesn't believe in 100 Day honeymoon periods for new presidents); Obama's positions on every possible contingency may not have been fully-formed yet, or they might not have been known to Ross (who was himself in a state of flux in late-April: unwanted by Clinton at State, but not transferred to NSC until June). Ross could simply have been out of the loop. Perhaps that's a lame excuse, but whatever the reason I don't think it alters Obama's fundamentally realist orientation towards Iran. Whether or not it works is another matter...