Trump writes a new playbook for quagmires in Gaza and Ukraine

His blueprints for both places are rejections of U.S. policy going back decades, a stark assertion that Washington’s conventional answers to these seemingly interminable clashes have been tried and have failed.

To Trump, Gaza and Ukraine look much the same. Thousands die needlessly. Cities lie in ruins. Ancient hatreds fuel endless fighting. His solutions share much in common as well.

They stem from his belief in his powers of persuasion, a stated yearning to be seen as a deal-cutting peacemaker of historic significance, and a penchant for imposing solutions on weaker countries, including allies, said analysts who have studied both conflicts.

“What he wants in both situations is quiet, peace, a deal," said William Wechsler, the senior director of the Rafik Hariri Center and Middle East Programs at the Atlantic Council, a think tank. “Less American engagement and less American risk."

A question is whether Trump might now try his game plan elsewhere, such as in Taiwan, where fears are growing that the president’s desire for a quick trade deal with Beijing might inspire him to use the democratic island as a bargaining chip.

Trump’s unorthodox approach also risks creating new strategic dead ends.

In Ukraine, Trump’s push for peace has inspired some fears in Kyiv that he might seek a deal without the country’s buy-in that brings a temporary halt to fighting but doesn’t provide Ukraine with enough support to resist Russian efforts to subjugate it in the long term.

As Trump disclosed Wednesday that he and Russian President Vladimir Putin had agreed to begin talks on a peace deal, Defense Secretary Pete Hegseth was laying out in Brussels the parameters of a possible agreement that ruled out Kyiv’s reclaiming all of its Russian-seized territory, as well as Ukrainian membership in the North Atlantic Treaty Organization and the deployment of U.S. troops as peacekeepers.

European officials said the administration’s concessions surrendered Trump’s leverage before talks even began.

“Trump always speaks about ‘peace through strength,’ and that is precisely the right approach with the Russians," said a senior European official. “But here we have not really seen the strength part yet."

While Trump vowed in comments to reporters Wednesday to continue U.S. military aid to Kyiv, he insisted that Putin’s desire for peace is genuine, a sentiment some analysts said is doubtful.

“Trump wants a cease-fire and some kind of arrangement that would sideline the Ukraine issue for a while,“ said Tatiana Stanovaya, a senior fellow at the Carnegie Russia Eurasia Center, in a post on X. “But his vision still differs radically from Putin’s. For Putin, a real solution means a Ukraine that is ‘friendly’ to Russia."

In 2016, Trump barnstormed his way to the presidency by blaming Washington for launching long-term occupations in Afghanistan or Iraq, with little to show for it. But he often found his own ideas blocked by his own advisers and his own unfamiliarity with policymaking.

The peace deals that he did push through in his first term were also unconventional—and yielded mixed results.

The normalization pacts between Israel and four Arab states—the Abraham Accords-—discarded decades of thinking in Washington and Middle East capitals that the century-old conflict required a Palestinian state for peace. But it didn’t catch on with other Arab countries. Hamas cited the sidelining of the Palestinian cause as a rallying cry for the Oct. 7, 2023, attacks that sparked the war with Israel.

Trump bucked Washington’s establishment in 2020 by striking a peace accord with the Taliban that didn’t include the U.S.-backed Afghan government. While the Biden administration was roundly criticized for its handling of the final troop withdrawal, many longtime observers of Afghanistan blasted the accord for not constraining the Taliban from restricting the education of girls and other hard-line policies.

In his second term, Trump is already proving more willing to pursue his own ideas.

“We inherited a world on fire thanks to a generation of so-called experts from the foreign-policy establishment," said Brian Hughes, a National Security Council spokesman. “President Trump is quickly reversing their terrible mistakes, and America is once again the dominant force for peace and stability."

Trump’s threats to seize the Panama Canal, to make Canada a U.S. state and to take control of Greenland have alarmed U.S. allies.

In Gaza, his plan to relocate the nearly two million Palestinians to Jordan and Egypt so the U.S. can “take" and rebuild the shattered enclave has been rejected by Arab governments and some Gazans who have said they would never abandon their homes.

No previous White House since the founding of Israel in 1948 has suggested the permanent removal of Palestinians from Gaza, which most U.S. presidents have seen as a part of an eventual Palestinian state.

But Arab and Israeli public support for side-by-side states has waned dramatically, especially since Oct. 7.

Trump sees all of the region’s players trying to turn the clock back to before Oct. 7, said Wechsler. The president’s plan to remove Palestinians from Gaza and have the U.S. take ownership of the strip for a real-estate project is designed to shake up a region that he sees as stuck in the past.

Yet Trump’s proposal is also one that people in Israel and the Arab world regard as unrealistic, with the potential to destabilize such countries as Egypt and Jordan that border Israel.

“Gaza seems like a nonstarter at best, which makes me wonder if it isn’t just a wild gambit to kick-start diplomatic paralysis with either the Egyptians and Jordanians," said Reid Smith, vice president for foreign policy at Stand Together, a nonprofit founded by the Koch family.

Trump’s ideas for Gaza and Ukraine are being watched by other U.S. allies and adversaries, wondering if he might try similarly disruptive ideas in Taiwan and other hot spots.

For decades, Washington has been Taipei’s most important military backer, supplying the weapons needed to deter and defend against a potential attack by China. Beijing claims the island as its territory and hasn’t ruled out the use of force in asserting control over it.

“If China harbors doubt that the U.S. is going to follow through on its commitments to Taiwan, then we are not deterring China, we are tantalizing and emboldening China," said Daniel Russel, a former U.S. diplomat and now vice president at the Asia Society Policy Institute in New York.

The tense peace that exists rests on an array of agreements, understandings and practices that govern China-Taiwan relations, and they reflect delicate language and raw power honed over decades.

Trump has mostly stuck to the traditional “strategic ambiguity" messaging over whether the U.S. would get involved in a China-Taiwan conflict that has been Washington policy for decades. But he has at times spoken in transactional terms about the island.

“The big question is whether the president thinks a grand bargain with Beijing, one that might include Taiwan, is possible," said Richard Fontaine, chief executive of Center for a New American Security, something he said few around the president consider realistic or desirable.

“That would be very unconventional," Fontaine said.

Write to David S. Cloud at david.cloud@wsj.com, Alexander Ward at alex.ward@wsj.com and James T. Areddy at James.Areddy@wsj.com