Were Hillary Clinton our president, the United States would probably be at war now with Syria or Iran or both.

Even as Nancy Pelosi and crew do everything they can to remove President Trump from office, there is one reason Democrats and Republicans together should be thanking God he won in 2016.

The Trump administration this week announced that Syrian dictator Bashar Assad used chlorine weapons against his own people back in May. Trump is right to promise some sort of retaliation. He is also right not to pursue yet another regime-change war.

Trump in 2016 distinguished himself from Clinton and from Republican orthodoxy in many ways. Most consequential, perhaps, was his dissent from the bipartisan foreign policy establishment. The Democratic establishment preaches and practices the doctrine of aggressive humanitarian interventionism. The Republican establishment has been pulled by the similar but competing pulls of democracy-promotion on the one hand and unflinching militarism on the other.

The bipartisan elite consensus has thus yielded multiple wars that have no direct bearing on American security or American interests. On the international stage, the results have been utterly disastrous. On the domestic front, these wars helped bring about Trump's election, to the utter shock and dismay of the same bipartisan establishment that created our foreign policy problems.

Barack Obama’s regime-change war in Libya was a colossal mistake. The resulting power vacuum has created a breeding ground for terrorists, extremists, and militarists in the time since: “scumbag Woodstock,” as counterterrorism experts would call it. When Trump said Obama created the Islamic State, he wasn’t completely wrong — except that he should also bring up George W. Bush’s regime-change war in Iraq each time he uses such language.

The Iraq War completely undermined U.S. interests and created new opportunities for Iran to menace the region. Bush, singing hymns about spreading democracy throughout the world, sent the military to chase ghost weapons of mass destruction. Those were never found, but the war did empower terrorists, costing the lives of thousands of Americans and more than a trillion dollars all told.

Moammar Gadhafi and Saddam Hussein were bad men — evil, even. The world, as so many put it, is better off without them. That doesn’t justify the U.S.-led wars to depose them. It doesn't mean either war was a good idea.

Likewise, Bashar Assad is a vile murderer and a dictator. Many Republicans and Democrats have long called for the U.S. to do to him what we did to Gadhafi and Hussein. And for similar reasons, that would be a mistake. There is no direct connection between ousting Assad and protecting America. America’s ample war-making might ought to be put to work to defend America, to demolish those who would kill us, and to uphold mutual defense pacts. This is what Trump means when he says “America First.”

Because there is a global commitment to ending the use of chemical weapons, there might be a very limited U.S. role here, if we can wipe out Assad’s chlorine stockpiles. But that would not justify roping us into yet another war that would make things even worse, as history has shown. This is the single most important lesson from 21st century American politics so far, and it would be just plain stupid to ignore it.

Conservatism includes an understanding that dramatic changes to complex situations tend to introduce unintended consequences, most of them evils. Trump, who was never much of a political conservative, has nonetheless proven that he possesses and embraces this key aspect of conservatism. For that, everyone who learned a lesson from Iraq or Libya should be grateful.