THE NEWS SAYS: Trump is right to reassess our approach.

Monday night, the military’s commander in chief stood before troops and a war-weary nation to explain what he described as a “dramatically different” strategy to win the 16-years-andcounting conflict in Afghanistan. Donald Trump, a longtime advocate of withdrawal who was persuaded otherwise after an exhaustive review, is right to reassess our approach.

The large and largely lawless land, from which the Sept. 11 attacks were launched, must never again become a spawning ground for terrorists who plot to kill Americans.

But while the President soundly made the argument against precipitous withdrawal, a lesson learned from a too-swift U.S. pullout from Iraq that helped spawn ISIS, he failed to rally the nation affirmatively behind his supposedly new plan.

In fact, the strategy Trump trumpets as a sharp turn from previous efforts sounded, to the extent that there were any details at all, awfully similar to what President Obama outlined in 2009.

Use all elements of American power — political, economic, diplomatic and military? Check. Pressure Pakistan to help root out terrorists? Check. Respond flexibly not to preset timetables but to conditions on the ground? Check.

The echoes were clear as day, with an asterisk: Whereas Obama committed to a troop increase from about 30,000 to roughly 100,000, Trump gives no indication about how many more of America’s sons and daughters he will send to bolster the now 8,400 military personnel in country.

Unofficial reports Monday put the figure at about 4,000 — which, if true, would have little long-term effect on dynamics on the ground.

But Trump keeps troop levels in a black box, saying, “America’s enemies must never know our plans or believe they can wait us out.”

No doubt it would be suicidal to reveal actual battle strategies to Al Qaeda and its allies. But to extend this logic to the mere size of a U.S. fighting force is too facile by half.

A war effort cannot succeed without sustained homefront support. Sustained homefront support is impossible without such clarity.

Further, while arbitrary withdrawal timetables are indeed unwise, it is disingenuous to suggest that simply hinting at an indefinite commitment will break the enemy’s will.

Afghani insurgents “believe they can wait us out,” to use Trump’s words, because they can wait us out. They live there; we do not.

The only solution to this problem is to ensure Afghanistan’s chronically corrupt and dysfunctional government can manage, in America’s necessary eventual absence, to prevent spiraling downward into the Taliban and terrorist death grip.

Reducing the job to solely “killing terrorists,” and never “nation-building,” Trump Monday belittled that crucial piece of the job.

So, too, was it dishonest for the President to marshal as rationale for a prolongued commitment to Afghanistan the terrible van attack in Barcelona.

Not only because those attackers were from Morocco, but because a report released just Monday confirmed that over the course of 2016, even as ISIS’ fighting forces and territory in Iraq and Syria shrunk, the frequency and lethality of attacks in western nations accelerated.

“Yes, we will defeat them, and we will defeat them handily,” proclaimed the President.

The success of his bold pledge hinges on the effectiveness of a strategy that, to the extent seen, sounds similar to past efforts — and to the extent unseen, must be taken on faith.