Analysis: Two-page summit document offers only what failed in the past.

WASHINGTON — The diplomatic history of U.S.North Korean relations is littered with broken promises to denuclearize and deals gone sour.

At their meeting in Singapore on Tuesday, President Donald Trump and North Korean leader Kim Jong Un signed a document, with scant details and more vague wording than those that have failed in the past to bring peace to the Korean peninsula and rid it of nuclear arms.

The summit, for all the anticipatory hype, was never expected to produce much in the way of new policies or strategy. But it actually produced less than many analysts expected.

The meeting did succeed in turning down the heated rhetoric, shifting the relationship to one of diplomacy instead of threatened war and suggesting a new, tentative rapprochement between two longtime foes.

“If the bar for success in this summit is war or peace, it’s a pretty low bar,” said Victor Cha, an Asia specialist in the George W. Bush White House. “We got peace.”

But the absence of specifics hands a gargantuan task to Secretary of State Mike Pompeo and other American negotiators who must translate what Trump described as a congenial spirit of cooperation into concrete steps.

In the months, even years, to come, Pompeo and his team — and perhaps their successors — will have to try to set out ways to begin dismantling Kim’s arsenal and the timing and verification of those actions.

The United States and North Korea have still not agreed on the very definition of denuclearization; as far as is known, Kim did not even offer a declaration of the components of his nuclear, chemical and biological arsenal, a step many experts considered to be fundamental.

“We’ve bought time, we averted confrontation, but you needed a much more robust denuclearization process,” said Scott Snyder, director of the U.S.-Korea policy program at the Council on Foreign Relations.

“President Trump was in full salesman mode and didn’t have that much to sell,” Snyder added.

Buying time is a talent the North Koreans have perfected, one that takes advantage of the fact that U.S. officials have many other priorities to occupy their attention.

For the U.S. now, “what is important is not to declare victory and go home, but to maintain the momentum,” said Joel S. Wit, a veteran negotiator on a nuclear deal with North Korea in 1994 that later collapsed. “Senior Americans have to stay involved and focused.”

In the summit, Trump and Kim treated each other with great respect. Kim addressed Trump with honorifics in Korean, and Trump called Kim warm and talented, unusual praise for a despot with such a brutal human rights record.

Cha, the former Bush adviser, said the personal chemistry was important but not sufficient.

“How will this be reciprocated?” Cha said. “When Donald Trump goes to Pyongyang, Kim Jong Un will treat him really nicely — but he’ll still keep his nuclear weapons.”

American skepticism about North Korea is born of history. In addition to the 1994 deal that broke down, the North Koreans also pledged in 2005 to denuclearize. In 2012, shortly after ascending to the leadership of his country, Kim Jong Un agreed to a moratorium on long-range missile launches, nuclear tests and production of fissile material. Only six weeks elapsed before North Korea tried to launch an intercontinental ballistic missile.

And despite the warmth between Trump and Kim on display in Singapore, the distrust between the United States and North Korea runs long and deep.

Beyond the issue of trust, the physical process of denuclearization could take 10 to 15 years, meaning that implementing any deal — assuming that one is eventually negotiated — would require more than one administration.

Verifying that North Korea was living up to an agreement would likely require experienced nuclear inspectors and Koreanspeaking scientists who can go through North Korean records to account for the fissile material the country has produced.

North Korea has produced enough plutonium to build 30 to 60 nuclear warheads, which are most likely hidden deep in its mountainous terrain. Although North Korea’s nuclear reactor at Yongbyon is well known and clearly monitored by satellites, the U.S. does not know the location of some of the centrifuges used to produce highly enriched uranium.

“Everything has to be done in phases so that we can watch each other over a period of years,” Wit said.

Trump’s critics complain that the president has been looking for a quick political victory, not a lasting solution to the dilemma that is North Korea.

“He is so vested in success. Trump wants everything to be fast. He’ll say: ‘This is great. Where’s my Nobel Prize?’ ” said Daniel Russel, an assistant secretary of state for Asian affairs in the Obama administration.

Trump touted as a concession from Kim an agreement by North Korea to help recover remains of U.S. servicemen lost in the Korean war. That, too, was a repeat of past deals.

Although Trump portrayed the agreement he signed with Kim as “comprehensive,” Russel said “it was little more than a cut and paste” version of past declarations — if that. And Trump’s plan to end joint U.S.-South Korean military exercises was ill-advised and a “lopsided” concession, Russel said.

“Not only did Trump buy the same horse again, he paid retail,” he said.