If President Trump isn’t careful, his North Korea concessions will soon resemble President Barack Obama’s pre-nuclear-deal gifts to Iran.

Trump denies ever making concessions to Pyongyang strongman Kim Jong-un. But last week the Pentagon announced the cancellation of the Vigilant Ace exercise, the annual winter drill America and South Korea jointly conduct to prepare for North Korean aggression.

The Department of Defense said the exercise’s “suspension” was done in support of Trump’s Pyongyang diplomacy. So how’s that going?

Secretary of State Mike Pompeo went to Pyongyang two weeks ago for the fourth time. He lunched with Kim and quickly left town. Ostensibly the lunch was about charting a second Trump-Kim summit, the date and venue of which are yet to be announced.

But Pompeo told reporters the North also agreed to allow outside inspectors into Punggye-ri, a nuclear site Pyongyang claims to have dismantled. The inspectors will arrive once “logistics” are worked out, Pompeo said, acknowledging however they won’t be allowed into Yongbyon, the site where real nuclear work is conducted.

Meanwhile Tomás Ojea Quintana, a UN human-rights observer, notes that North Korean atrocities aren’t even on the agenda in the disarmament talks. And as he told reporters Tuesday, “The situation on the ground, according to information I gathered this year, indicates there’s no change” in the horrors Kim inflicts on his people.

In other words, the planned Trump-Kim summit will be marked by little real progress beyond atmospherics. And the arms layoff.

The latest Pentagon’s announcement resembled last spring’s cancellation of the Ulchi Freedom Guardian drill, the summer joint exercise, on the eve of the Singapore summit.

Not to be outdone, Seoul this week announced it and Pyongyang agreed to remove troops and arms from their border.

South Korean President Moon Jae-in’s “Moonshine policy” consists of endless concessions, gestures and showering love on Kim, so his latest actions are no surprise. But what explains Trump? Especially given how he endlessly takes Obama to task for handing Iran “bribes”?

Trump claims his opening to Kim is easily reversible. “We gave nothing,” he insisted on Fox News after the Singapore summit. Besides, canceling military exercises saves us a lot of money. And they can resume as soon as Trump so orders.

Well, not quite. The Vigilant Ace exercise involves up to 12,000 US and South Korean troops and many aircraft and naval assets. It requires complex coordination and long-term preparation. Once canceled, it’ll remain canceled, at least for this year.

But what if, heaven forbid, Kim, a ruler known to act erratically, renews aggressive missile or nuke testing? Or his missile launches? Will we be ready?

Trump rightly notes that Pyongyang continues to face pressure. We’ve yet to remove the sanctions cobbled together by outgoing UN Ambassador Nikki Haley, which clearly hurt the North. But according to a leaked draft of a new UN report, Russia, China and others already violate those sanctions. (The draft has yet to be officially issued, as Russia is demanding its culpability be edited out.) And Moon has been asking for sanctions exemptions for pet joint projects with North Korea.

A global sanctions regime, as we learned from the run-up to the Iraq war, can be watered down and lead to war. Canceling military drills as a goodwill gesture sends the wrong signal about America’s resolve to keep the heat up. It’ll only hasten an end to tough sanctions.

And remember: Trump actually favors pressuring adversaries by displaying military might. This week, the US Navy concluded a high-profile display of defiance by sailing ships through the Taiwan Straits. Trump knew how much that would anger China but sought to signal America’s commitment to freedom of navigation and to the defense of our ally, Taiwan.

Sure, sometimes goodwill gestures could bolster diplomatic efforts, but Kim isn’t versed is such nuances. Worse: We have little reliable intelligence about Pyongyang’s goings-on, and what we do know is often colored by Seoul’s increasingly rosy glasses.

Trump rightly criticizes Obama’s clumsy attempt to declaw Iran by showering it with gifts. Yet his eagerness to turn the Korean Peninsula into a peaceful oasis, preferably before the 2020 election, is leading him to take a similar approach with the Kim regime.