But Trump is also correct in suggesting that the current global system is an aberration in American history, that it may not be sustainable forever under current conditions, and that America should focus more on fixing our own economic house for a long time to come (a view shared, incidentally, by Barack Obama, who loves to say “it’s time to focus on nation-building at home”). The U.S. share of global defense spending has soared to more than a third of the total, while the American economy has dropped in size to one-quarter of global GDP; America spends more in total than the next seven largest countries combined: China, Saudi Arabia, Russia, Britain, India, France and Japan. And to what end exactly? No one can quite say. “Since the end of the Cold War and the breakup of the Soviet Union, we’ve lacked a coherent foreign policy,” Trump said in his speech. This is also arguably true. From Bosnia to Kosovo to Iraq, America has bounced around from idea to idea and intervention to intervention—from the idea of “humanitarian war” to the idea of “preventive war.” There is nothing even close to the ragged consensus that existed over Cold War containment.

So Trump may be an “id with hair,” as Hillary Clinton calls him, but at least when it comes to his foreign policy views, he’s an all-American id. His “America First” campaign theme has far deeper roots in the history of this country than most pundits are acknowledging. Indeed, Trump shouldn’t be dismissed as a mere apostate in his view of America’s role in the world; against the backdrop of all 239 years of America’s existence, he represents more a reversion to the American norm. Trump, in condemning one of the worst instances of American overreach in U.S. history, the Iraq invasion, declared in his speech: “The world must know we do not go abroad in search of enemies.” The line was an allusion to the famous injunction of John Quincy Adams in 1821 that America “does not go in search of monsters to destroy. She is the well-wisher to the freedom and independence of all. She is the champion and vindicator only of her own.” Adams went on to warn, somewhat presciently, America should know that “once enlisting under other banners than her own, were they even the banners of foreign independence, she would involve herself, beyond the power of extrication, in all the wars of interest and intrigue, of individual avarice, envy, and ambition, which assume the colors and usurp the standard of freedom. The fundamental maxims of her policy would insensibly change from liberty to force.”