President Trump has begun bombing Syria. Having found domestic policy difficult, complicated, and time-consuming, he has turned to foreign affairs to try to strike a pose of confidence and decisiveness. He started earlier in the week with North Korea because he was looking for the softest, least controversial target. It gave him something to look tough on given the impending meeting with the Chinese president.

But now he’s turned to something far more committal in Syria, and he’s made the decision in almost no time. Not only does this give the lie to the claim that Trump is Putin’s Manchurian Candidate, given Russia’s alliance with Syrian dictator Bashar al-Assad, but it’s a sign of just how reactive and incoherent Trump’s approach to foreign policy is. Considering the swiftness with which he decided to send in the Tomahawks and warplanes, he can’t have put much thought into it at all. He just saw it as a chance to act, to be the kind of leader he imagines himself to be.

But there is no escaping politics. Bombing Syria changes the situation with ISIS, and with the Kurds in northern Syria, which changes things for the Turks. The Russians have other interests here, not to mention that there are Russians in Syria who could get hit by a stray missile. The Russians have denounced the strikes. There are laws (thin as they are) regulating the use of force abroad without congressional authorization. Trump is going to have to explain the goal and endgame. Having said publicly he has changed his mind about Assad, he has given the impression that he wants regime change — but how?

And if Trump isn’t really serious about carrying on, then he faces a different problem. He will be accused of not being able to follow through. That will make him look weak and ineffective, which in his world is quite possibly the worst possible thing. That’s a problem he can only solve with more aggression. In which case many Syrians will pay for his vanity, ineptness, and lack of political skills.

But this is not just a story about Trump’s individual failings. We’ve been here before. America’s imperial presidents have long found violence abroad a more convenient way of exercising power than the slow boring of hard boards at home. Democracy, or even just our half-baked excuse for it, is messy and difficult, but it is weakest when it comes to war. George H. W. Bush explained it this way in 1992: “Some people say, why can’t you bring the same kind of purpose and success to the domestic scene as you did in Desert Shield and Desert Storm? And the answer is: I didn’t have to get permission from some old goat in the United States Congress to kick Saddam Hussein out of Kuwait.”

Nor is this merely a Republican perspective. Bill Clinton was downright proud that intervening in Haiti went against public will: “I realize it is unpopular. I know it is unpopular. I know the timing is unpopular. I know the whole thing is unpopular. But I believe it is the right thing.” As if the value and purposiveness of an act of violence internationally varies inversely with its democratic credentials.

Some blame also has to be laid at the feet of those who have championed humanitarian intervention. It is they who have set the tone for the kind of foreign policy that, without any consultation of Congress or real argument to the public, decides a gas attack justifies launching missiles. It is they who have made it look like the highest form of moral action is the “brave” decision to go to war.

When you turn foreign policy into something in which presidents act on behalf of distant victims rather than their own public, all you really do is weaken those remaining democratic controls over a runaway executive.

And in the end, this is a thin humanitarianism, since one never finds the humanitarian militarists arguing the true humanitarian case: not bombs but open borders. Let in anyone who wishes to escape.