The nuclear summit between President Donald Trump and North Korean leader Kim Jong Un has concluded, with each securing something they value. The US will suspend the joint military exercises with South Korea that rattle the Hermit Kingdom. And North Korea has promised to denuclearize. At some point. Probably. But if the past is any sort of prologue, you shouldn't hold your breath.

On the face of it, the agreement signed by Trump and Kim seems promising. “President Trump committed to provide security guarantees to the DPRK, and Chairman Kim Jong Un reaffirmed his firm and unwavering commitment to complete denuclearization of the Korean Peninsula,” the statement read.

But this is not the first time North Korea has promised to abandon its nuclear efforts. (In truth, even this was simply a reaffirmation of a denuclearization pledge Kim had already made in April.) Nor is it the second time, or the third. The offer has resurfaced over the past several decades with surprising regularity. And it has never panned out so far.

“There’s definitely a pattern where the North Koreans agree to denuclearize in theory, but then there’s not really a substantive process that they agree to, to actually hammer it out,” says James McKeon, a policy analyst at the Center for Arms Control and Non-Proliferation.

'Any notion that we’re simply going to denuclearize North Korea now after the summit, or any time in the very near future, must be dispelled.' James McKeon, Center for Arms Control and Non-Proliferation

Those failures don’t necessarily come down to bad faith, or at least not entirely. In fact, the 1994 Agreed Framework between the US and North Korea, in which the North gave up its plutonium enrichment in exchange for aid, resulted in a roughly eight-year stretch of calm. That eventually collapsed too, though, as North Korea’s pursuit of enriched uranium and the George W. Bush administration’s hawkish stance imploded the already shaky scaffolding.

But in general, North Korea uses denuclearization as a bargaining chip in times of desperation. “Usually they suffer some kind of internal crisis, and then start acting in a really threatening way to try to get people to give them stuff,” says Mieke Eoyang, a national security analyst for center-left think tank Third Way.

In this instance, Eoyang argues, Trump gave the longtime US adversary far too much. “It’s substantively worse than what any other president has done,” she says, noting that the joint exercises aren’t just for show. The US rotates troops in and out of South Korea every few years; training with local counterparts helps newly stationed units prepare for potential North Korean aggression.

In return for that real loss, the US gained the same promise North Korea has made since 1985, without a single specific about how to accomplish it. There’s no agreement on inspections. North Korea doesn’t have to declare the facilities it has, much less dismantle them, to say nothing of destroying actual warheads.

“It is much messier at the working level, particularly when it comes to verification,” says John Carl Baker, a political engagement specialist at Ploughshares Fund, a grantmaking foundation that focuses on denuclearization. “As an analyst, I’m skeptical that this is the time that it’s finally going to come together. I’m certainly skeptical of the fact that the North is going to completely denuclearize itself.”

Add to this uncertain stew the fact that Trump very recently tore up a nuclear inspection framework that was actually working in Iran, and it’s hard to see how or why North Korea would go through with a promise that it has broken time and again. Especially this time.

“It sent the the absolute wrong message,” says CACNP’s McKeon of scrapping the Iran deal. “Any notion that we’re simply going to denuclearize North Korea now after the summit, or any time in the very near future, must be dispelled.”

Some North Korea observers did strike hopeful notes; both McKeon and Baker think the summit was an important first step, however symbolic. And it was certainly an improvement over the overt nuclear threats of a few months ago. But this script has been written before, and always with the same ending. See for yourself (and for a more thorough dissection, check out the Arms Control Association’s comprehensive timeline):