After President Trump walked out of his talks with Kim Jong-un in Hanoi over North Korea’s demand for an end to “sanctions in their entirety,” Democratic leaders were ecstatic. “I’m glad,” House Speaker Nancy Pelosi told reporters. “They wanted lifting sanctions without denuclearization.” In a giddy aside, Pelosi added that Trump had finally realized that Kim “is not on the level.”

Senate minority leader Chuck Schumer chimed in, declaring on Twitter that Kim’s deal “would have only made North Korea stronger & the world less safe.” Their response was quite a shift for a party that questions Trump on practically every front, from immigration to health care to Russia. But this was about North Korea, and Democrats have been cynical about Trump’s talks with Kim and the inter-Korean peace process from the beginning.

Even before Trump went to Singapore last year for the first-ever meeting between a US president and a North Korean leader, Schumer and six other senators warned that they would reject “any deal that explicitly or implicitly gives North Korea sanctions relief for anything other” than the complete dismantling of its nuclear and missile programs. In February, Senator Bob Menendez, the ranking Democrat on the Foreign Relations Committee, sent another letter attacking South Korean President Moon Jae-in for seeking sanctions relief to aid his push for closer economic ties with the North. Joined by Republican Senator Ted Cruz, Menendez demanded that Trump must ensure “the integrity of the sanctions regime.”

As if this weren’t enough, a week before the Hanoi summit, Pelosi arrogantly lectured South Korean lawmakers seeking support for their engagement policy not to trust Kim. Worse, she urged them to end a nasty quarrel with Japan over its war crimes during World War II as part of a misguided attempt to create a united front against North Korea. That led the speaker of the National Assembly—Pelosi’s counterpart in South Korea—to accuse her of carrying water for Shinzo Abe, Japan’s right-wing leader. Abe, meanwhile, was just as chipper as the Dems at the collapse of the Hanoi summit.

But the Democrats were hoodwinked into buying Trump’s explanation for his failure. In fact, the president and John Bolton, his national-security adviser, were extremely misleading about the deal they rejected. This became clear within hours of Trump’s departure, when North Korean Foreign Minister Ri Yong-ho publicly rebutted Trump’s claims. In return for shutting down its massive—albeit aging—Yongbyon nuclear complex, the North, it turned out, had asked Trump to remove the sanctions imposed on the country only after 2016, not the entire sanctions regime. Kim, said Ri, had focused on five UN sanctions that “impede the civilian economy and the livelihood of our people.” Moreover, Ri announced that North Korea had been ready to offer, in writing, a permanent halt to its nuclear and ICBM tests. Even the Associated Press, well-known for its evenness in foreign reporting, had to ask of the sanctions: “So who’s telling the truth? In this case, it seems that the North Koreans are.”

President Moon expressed his disappointment with the outcome. Should Yongbyon “be fully and completely dismantled,” he told his National Security Council, “North Korea’s denuclearization process could be said to have entered an irreversible stage.” His foreign minister, Kang Kyung-wha, said Seoul would seek three-way talks with Washington and Pyongyang to jump-start denuclearization talks. Kim Jong-un, meanwhile, issued a conciliatory statement through KCNA, the state-run news agency, expressing appreciation for Trump’s “active efforts towards” results and vowing to meet again.

Despite this gesture, Trump’s final act in Hanoi made the situation even worse. After State Department and Treasury officials convinced Trump that the relief sought by Kim would give North Korea billions of dollars that it could pump back into its nuclear and missile programs, Trump came back with one of his trademark grand gestures that he foolishly hoped Kim would accept. It was “the big deal that could make a difference for North Korea,” Bolton proudly told Fox News. Under Trump’s new formulation, as Bolton explained on CBS, “if North Korea commits to complete denuclearization—including its ballistic-missile program and its chemical- and biological-weapons programs, the prospect of economic progress is there.”

But this gambit—which vastly expanded the working US definition of “denuclearization”—was bound to fail. First, the demand on chemical and biological weapons (which Schumer and the Democrats had backed in their 2018 letter) was added at the last minute by Bolton. Second, Trump was now demanding a total surrender of Kim’s weapons arsenal as the condition for relaxation of any sanctions. That’s a deal that North Korea has constantly rejected, going back to the Bush and Obama years. Even when the North’s inconsistent negotiating record is considered, this was a colossal—and bipartisan—blunder.

Sadly, Trump’s cold response to the death of Otto Warmbier, the Virginia student who was returned from North Korean captivity in a coma and later died, has given Democrats more ammunition to go after the peace process. “I will take him at his word,” Trump said about Kim’s assurances that he was unaware of Warmbier’s condition until his release.

In response, Democratic Representative Tom Malinowski, a former Obama official who in 2017 called for regime change in North Korea, introduced a congressional resolution to hold Kim personally responsible for Warmbier’s death. He later withdrew it at the request of the Virginian’s family. Still, a full investigation of the facts—which should include questioning US diplomats and intelligence officers as well as Warmbier’s doctors—might be useful to the public’s full understanding of what really happened to him during his captivity and the efforts that led to his release.

Overall, Democrats taking a hard line on North Korea should consider that no death should be used as a political weapon. Congress must join with South Korea in keeping the peace talks alive, so that we can bring an end to America’s longest war and help the two Koreas reconcile after 70 years of division and conflict. There really is no other choice.