From the moment Donald Trump began his campaign for president, he displayed a remarkable knack for exposing the incoherence lying just beneath the surface of the Republican Party's governing ideology.

The GOP claims to champion the interests of ordinary Americans, but its policies favor elites at the expense of everyone else. The party portrays itself as a defender of the nation's borders, but it has permitted millions of undocumented immigrants to enter and remain in the country. It asserts the importance of keeping America militarily strong but it pursues policies (like the Iraq War) that demonstrate our weakness. Most Republican politicians try to obfuscate and obscure these internal contradictions. Trump shines a light on them and roars.

As president, Trump has accomplished a similar unmasking of the contradictions at the heart of Washington's bipartisan foreign policy consensus. In his speech Tuesday to the United Nations General Assembly, Trump sometimes sounded like a booster of the U.N. and the liberal internationalist order it was founded to buttress. At other points, he echoed the "America First" themes of his presidential campaign, defending the inviolability of national sovereignty and allowing each nation to determine its own fate. In other passages, he spoke like a unilateralist neocon circa 2002 about the need for the U.S. to use military force against "rogue regimes" (like Iran, Venezuela, and of course North Korea) that pose a threat to global order, American interests, freedom, and democracy.

It was an incoherent muddle of a speech — but not so much because Trump is abnormally incoherent as because he's less capable of (or interested in) finessing the incoherence that marks nearly all thinking about foreign policy in and around the nation's capital.

Democrat or Republican, center-left or center-right, liberal internationalist or neocon — commentary on American foreign policy tends to treat these divides as real and important, but they rarely are. Every major party candidate, every major think tank, and every establishment news outlet agrees on the big issues and disagrees only occasionally about specific judgment calls.

This is true even about the Iraq War, on which significant public figures, like Barack Obama, strongly disagreed. Obama opposed the Bush administration's policy of invading Iraq and deposing Saddam Hussein, but the disagreement was about details that were unique to the situation in Iraq at the time. Eight years later, as president, Obama would pursue a very similar policy of invading Libya and deposing Moammar Gadhafi (with very similarly bad consequences for the country and the region), showing that his Iraq objection had little to do with a disagreement over principles.

What is the bipartisan foreign policy consensus in the nation's capital? That the U.S. should pursue its interests when formulating policy and acting in the world. That other countries should do the same, but only so long as their interests don't clash with ours. (This is typically treated as a more important consideration than whether or not the country is a democracy.) That when the interests of other countries do clash with ours, we will seek to resolve the dispute through international institutions. That when such efforts at internationalism fail, we are entitled to use, and are morally justified in using, our overwhelming military preeminence to ensure that we ultimately prevail. And that no matter which of these courses of action we undertake, the result will automatically benefit all people and nations of good will in the world.

In sum: What's good for America is good for everyone else as well (except for a limited number of evildoers).

President Trump's speech on Tuesday affirmed every one of these assumptions — as has every major foreign policy address by every American president in living memory. The primary difference was one of tone. Trump has little use for diplomatic niceties, favoring taunts, name calling ("Rocket Man" for North Korean dictator Kim Jong Un), and overt threats (to "totally destroy" North Korea). He also delights in singling out Iran for abuse, which marks a significant shift from the policy actively pursued by the Obama administration, but which also signals a point of continuity with longstanding American policy prior to Obama.

Overall, it was a standard presidential speech with more elbows thrown and less effort made to conceal the standard contradictions.

This is how it's possible for some to say the speech showed that Trump had discovered his "inner neocon," others to conclude it displayed the "nationalism" that fueled his campaign for the White House, still others to fasten onto its "Jacksonian" themes, and plenty more to say it just plain made no sense at all.

Every president claims to be standing up for high principle. Every president promises to do whatever is necessary to defend the country. And every president blithely assumes that the first necessarily entails the second.

In the end, it was an incoherent speech — but not significantly more so than all the others.