Gary Cohn had to know what he was getting when he agreed to become Donald John Trump’s chief economic adviser.

He was hiring on to a team led by someone who doesn’t take advice. Trump flies by the backside of his britches. So, when the president decided to impose punishing tariffs on imported steel and aluminum, Cohn had seen enough.

He bailed. He’s gone. Cohn has decided t leave Trump’s economic team.

Cohn believes in free trade. Trump the populist believes in protectionism, which on its face flies directly opposite from traditional Republican economic policy.

But that doesn’t matter one damn bit to Donald Trump. He got angry at something or someone, so he decided to take it out on our nation’s trading allies. Canada, Mexico and many friendly trading partners in Western Europe are going to feel the pinch of the tariffs. What’s more, they are discussing retaliation.

Can you say, um, trade war?

As for Cohn, he sought to advise the president against acting so impetuously. Nice try, Mr. Cohn. Again, you had to know the guy for whom you were working was prone to this kind of knee-jerk behavior.

He won’t leave immediately, according to statements issued by Cohn and the White House. What the hell! Why not just hit the road?

According to Politico: Cohn, known in his decades on Wall Street as a pugnacious trader, is not leaving the fight right away. He plans to stay on for at least a couple of weeks and continue to battle Trump and the White House nationalists to more carefully tailor the tariffs to avoid antagonizing allies and inviting retribution.

For all the good it does to surround himself with actual experts on trade policy, Donald Trump will remain his own closest adviser.

Except that he doesn’t know what he’s doing.