Sixteen years ago today, on March 20, 2003, the United States invaded Iraq. After a months-long propaganda campaign the likes of which the country had never seen, a majority of Americans supported going to war. After all, the Bush administration had told them over and over that it was an act of self-preservation, for if we didn’t invade then, Saddam Hussein, who probably had something to do with Sept. 11, 2001, would attack us with his fearsome arsenal of weapons of mass destruction.

As then-Vice President Richard B. Cheney put it, “Simply stated, there is no doubt that Saddam Hussein now has weapons of mass destruction. There is no doubt he is amassing them to use against our friends, against our allies and against us.”

It turned out to be the worst foreign policy disaster in American history, with more than 4,500 Americans dead, 32,000 wounded, trillions of dollars spent and a region thrown into chaos with the rise of the Islamic State just one of the eventual consequences, not to mention the hundreds of thousands of Iraqis who died. And what did we learn?

Democrats learned a number of things. Many of them, including figures like Hillary Clinton and John Kerry, learned that trying to look “strong” by supporting military adventurism makes you look anything but. And they learned that their worst fears about what such adventurism can bring came true.

For Republicans, it was a different story. President Trump, almost alone in his party, learned that we don’t want to do anything like that again. It’s almost certain that he came to that conclusion mostly for the wrong reasons, but it was one of the few ideas he had that did more good than harm. The rest of his party, however, didn’t even learn that.

It may have faded from most people’s memory by now, but in the 2016 presidential primaries the Republican Party was bedeviled by the question of Iraq, and specifically whether the war was a mistake. Though that was evident to every sane person in the country, it was a hard thing for those seeking to lead the party to admit, because their entire party couldn’t have been more enthusiastic about it at the time, and acknowledging the truth would mean criticizing the last Republican president.

It was particularly difficult for Jeb Bush, that president’s brother. But like him, most of the candidates fell back on saying something like, “If we knew then what we know now we wouldn’t have invaded,” putting the blame solely on faulty intelligence without questioning the ideas and the foolish arrogance that actually took us to war.

The one exception was Trump.

Yes, in typical fashion, Trump told a ludicrous series of lies about what a loud opponent he had been in 2003, even claiming that his opposition was so potent that the Bush administration sent a delegation to New York to beg him to tone it down. (In fact, he had said almost nothing publicly about the war and didn’t oppose it.) But by 2015, Trump was saying what no other Republican would. Here’s what he said in a debate in December of that year:

We have done a tremendous disservice not only to the Middle East — we’ve done a tremendous disservice to humanity. The people that have been killed, the people that have been wiped away — and for what? It’s not like we had victory. It’s a mess. The Middle East is totally destabilized, a total and complete mess. I wish we had the $4 trillion or $5 trillion. I wish it were spent right here in the United States on schools, hospitals, roads, airports and everything else that are all falling apart!

Trump ran for president saying he didn’t want to get entangled in more invasions like Iraq. But this wasn’t because he worried about the cost in human suffering or the threat to American interests, because he doesn’t care about human suffering and never demonstrated much conception of what American interests might be. His point was more that he wouldn’t invade someplace to spread democracy, nor would he favor military action to stop a genocide.

After all, whenever Trump talks about the U.S. military role around the world, he usually says that other countries should be paying us more for the maintenance of our hegemony, whether it’s NATO or South Korea or anyone else. Everything is transactional, and if Trump can’t see an immediate short-term gain, he’s not interested.

Which, all things considered, isn’t the worst foreign policy principle you could have. President George W. Bush showed us what the worst is: a naive belief that nearly any problem can be solved with the application of sufficient ordnance, you don’t have to concern yourself with the internal politics of the country you’re about to invade, and if you display sufficient will, it will all work out in the end.

That isn’t to say there aren’t many ways in which Trump has been a foreign policy disaster. He has sent the United States’ image in the world plummeting, subverted key alliances and withdrawn from important international cooperative efforts. But, so far, anyway, he hasn’t invaded anyone, no doubt to the chagrin of some of his advisers.

But there’s absolutely no evidence that anyone in the Republican Party learned much of anything from the Iraq disaster. The next Republican president will probably be just as eager to launch an invasion or two as the last one was. You don’t hear them talk about the lessons of Iraq, because they didn’t draw any.

Within the GOP, the Bush Doctrine — or at least the part of it involving the belief that American military force is a useful tool to shape the world to our liking, and unintended consequences are not really anything to worry about — lives on. It’s just in suspended animation until Trump is no longer leading the party.

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