Turkish jets struck a Kurdish base near the Iraq-Syria border late Monday night, the first grim fruits of President Trump’s decision to order US forces out of the way — a decision we fear Trump will come to regret.

We’ll grant that the president is delivering on a campaign promise here: Like most Americans, he doesn’t want this nation serving as the world’s policeman; other countries should share more of the burden when it comes to both troops and money.

Or, as he tweeted Monday, “it is time for us to get out of these ridiculous Endless Wars.”

He has a point, big-picture — but he’s making a big mistake here. Leaving Syria puts multiple US interests at risk. He’s not putting an end to “endless wars,” he’s planting the seeds for future ones.

For starters, Trump made the abrupt call to abandon US-allied Kurdish fighters and give Turkey the responsibility for captured ISIS fighters after a weekend call with Turkish tyrant Recep Tayyip Erdogan, who’s about as unreliable an “ally” as it gets.

Erdogan is responsible for letting many of those ISIS fighters enter Syria in the first place: An Islamist himself, he has long played both sides of nearly every conflict in the region. His only loyalty is to his own power.

Trump says he’ll use US economic power to hold Erdogan responsible for not letting thousands of now-captive ISIS killers escape, but that’s far from a guarantee that Turkish forces can prevent it. This invasion thus risks the revival of one of the most savage terrorist groups the world has ever known.

Renewed war — and the prospect of a long-term Turkish occupation of Syrian territory — is also likely to further destabilize the region.

But most importantly, we have betrayed the Kurds.

The Kurds have served as our allies in Iraq and Syria, and did much of the dirty work of putting ISIS down. Yet Erdogan views the Kurds as terrorists, and fears the Kurdish dream of an independent state. Erdogan’s troops will slaughter as many as they can.

The next group that Washington approaches to provide “boots on the ground” in some similar campaign — in the Middle East or anywhere else — will take note of how we treat our friends.

The president is right that it’s not America’s job to solve all the problems of the Middle East, but giving a green light to Erdogan’s invasion is all too likely to mean trouble down the road for the United States.