President Trump took the world aback with his declaration that the United States was going to “own” Gaza and move out the Palestinians there to build “the Riviera of the Middle East.” As unrealistic and bizarre as it may seem, Mr. Trump was pointing to a serious challenge: the future of Gaza as a secure, peaceful, even prosperous place.

A former French ambassador to Washington, Gérard Araud, put the dilemma neatly. “Trump’s proposal for Gaza is met with disbelief, opposition and sarcasm, but as he often does, in his brutal and clumsy way, he raises a real question: What to do when two million civilians find themselves in a field of ruins, full of explosives and corpses?”

That is an issue Israel’s prime minister, Benjamin Netanyahu, has always dodged. He has refused to engage on the question of who will rule Gaza after the conflict, largely because it would undermine his governing coalition, which depends on far-right parties that want to resettle Gaza with Israelis.

As outlandish and unworkable as Mr. Trump’s proposal on Tuesday may seem, it is “no less than an historic resetting of decades of received diplomatic wisdom,” said Chuck Freilich, a former Israeli deputy national security adviser. However unrealistic, he said, “it may force the sides to reconsider long-held positions, stir things up dramatically and lead to new openings.”

What Mr. Trump described — the forced relocation of two million Palestinians from Gaza to countries like Egypt and Jordan that are fiercely opposed to taking them — is not going to happen, said Lawrence Freedman, emeritus professor of war studies at King’s College London.

“Trump is a man who doesn’t want new military commitments, and now he wants to move two million people who don’t want to go to places that don’t want them,” he said. “But Trump picks up on a real problem, about how to reconstruct Gaza. The important thing with Trump is to pick out the real issues and deflect the stupid ones.”

In his news conference, Mr. Trump failed to discuss one of the biggest problems with his dream: Hamas, the armed Palestinian group devoted to the destruction of Israel. Hamas set off the war that has devastated Gaza and killed nearly 50,000 Palestinian civilians and combatants, with the Oct. 7, 2023, attack it led on Israel. Despite vowing to destroy Hamas and dismantle its control over Gaza, Israel has not achieved either goal, leading key far-right members of Mr. Netanyahu’s coalition to demand that the war continue after Phase 1 of the current cease-fire.

Mr. Trump has made it clear he does not want the fighting to begin again, but he also seems to have no answer to how to dislodge Hamas from Gaza, a precondition for getting help from many Arab governments to rebuild the enclave. The idea of American troops fighting and dying in Gaza seems implausible from a president who has wanted to pull them out of Afghanistan, Syria and Iraq. Keeping the peace to allow reconstruction and resettlement to take place would probably involve tens of thousands of American troops for perhaps a decade or more.

Trump officials were backtracking on some of his proposals on Wednesday, saying that any population transfer would be temporary.

But Hamas has made it clear it is going nowhere, and presumably it would fight American troops as it fought Israeli ones. As Basem Naim, a member of the group’s political bureau, said in a statement denouncing the Trump proposal, what Mr. Netanyahu failed to do with the support of President Joseph R. Biden Jr. — “to displace the residents of the Gaza Strip” in “carrying out genocide against our people” — “no new administration will succeed in implementing.”

Michael Milshtein, an Israeli analyst of Palestinian affairs, said that in discussions with Jordanian, Egyptian, Gulf Arab and Palestinian colleagues, “no one even wants to discuss this deal, because there will be no readiness of Hamas to evacuate Gaza, and I cannot find one Arab country or leader willing to accept the Palestinians.”

Even if nothing comes of Mr. Trump’s proposal, just floating it now is threatening the stability of Jordan and Egypt, two crucial allies in the Middle East with the longest history of diplomatic relations with Israel and, thus, is “strategically incomprehensible,” said Tom Phillips, a former British ambassador to Israel and Saudi Arabia.

Jordan already is more than half ethnic Palestinian, and for King Abdullah, who will meet with Mr. Trump next week, to accept more Palestinian refugees “would undermine the kingdom and be the end of the king,” Mr. Milshtein said, a judgment echoed by many. Already, many Jordanians are suspicious that there is “a Zionist conspiracy” to annex the occupied West Bank and create a Palestinian state out of Jordan, he and Mr. Phillips said.

Egypt may have more acreage and is in desperate need of American financial aid, but its president, Abdel Fattah el-Sisi, is a fierce opponent of Islamist radicalism, which he has tried to stamp out brutally in the Sinai, and of the Muslim Brotherhood, of which Hamas is a part. The notion that he would allow “hundreds of thousands of people supporting Hamas into Egypt” is unthinkable, Mr. Milshtein said.

Even at the height of the fighting, Mr. el-Sisi created a walled-off area near the border with Gaza in case Gazans were pressed into Egypt, to prevent them from going any farther. And Egypt, which considers itself the most important Arab country, would not want to be seen as being pushed around by Washington.

Christoph Heusgen, a former German ambassador to the United Nations who leads the Munich Security Conference, recalled that Jared Kushner, Mr. Trump’s son-in-law, talked of Gaza as great real estate last year, but then suggested resettling Gazans in Israel, in the Negev. Arab countries will simply refuse a population transfer, he said, “and the only other way is military force, and that’s genocide.” The Saudis are demanding a Palestinian state that Mr. Netanyahu opposes, and Mr. Trump “says he wants out of conflicts,” not to send American troops into another one, Mr. Heusgen said.

“It seems dead on arrival,” he said.

There has been serious diplomatic conversation, begun under Mr. Biden, of some sort of international grouping to oversee Gaza and its reconstruction that would involve officials from Saudi Arabia, Egypt, the United Arab Emirates and other countries under the aegis, at least, of the weak Palestinian Authority of Mahmoud Abbas. That presumes that Hamas will no longer be in control.

But Hamas has no intention of giving up its control or its aims, let alone disarming. It has expressed willingness to create an “administrative committee” to rule Gaza with other parties, including Arab countries and the Palestinian Authority, expanding on an Egyptian initiative. Such a committee is thought to be only a cosmetic cover that allows Hamas to retain control of security while reducing its responsibility for civilian governance.

Mr. Trump was silent on the future of an independent Palestinian state, which has become a crucial demand of Saudi Arabia after the destruction and death in Gaza. The Saudis were quick to oppose Mr. Trump’s plan in a statement overnight, and made it clear that any normalization with Israel, as Mr. Trump wants to promote, is dependent on concrete steps toward a viable independent Palestinian state, including Gaza. That is exactly the outcome that Mr. Netanyahu has vowed to prevent.

Simone Ledeen, former deputy assistant secretary of defense for the Middle East during the first Trump presidency, said Mr. Trump was setting out an initial negotiating stance. This is “a starting position,” she said. “It’s a negotiation — it’s the Middle East.”

Mr. Trump’s success in helping forge the 2020 Abraham Accords — bilateral agreements normalizing relations between Israel and some Gulf States — “hinged on setting aside the paradigm and recognizing that it’s broken,” Ms. Ledeen said, and now he is trying to reset the conversation. Mr. Trump spoke of American troops, she said, but “he’s left the door open for other parties to participate or take it over.”

Still, there remains enormous skepticism in the region about Washington’s ability to build statehood in the Middle East, after American failures in Iraq and Afghanistan, or about its willingness to stay the course over many years.

The Trump proposal also overshadowed the real and present problem in Gaza: whether Israel and Hamas will succeed in moving past this first phase of their cease-fire agreement to the much tougher second phase, which would involve Israeli concessions that Mr. Netanyahu has been so far unwilling to make. His coalition partners have vowed to bring down the government if he makes them and effectively ends the war with Hamas still standing.

Whether Mr. Trump, by his proposal, has helped Mr. Netanyahu assuage his partners remains to be seen — as well as whether Mr. Trump keeps the pressure on Mr. Netanyahu to make that deal regardless of the political cost.

President Trump’s statements on Tuesday about an American takeover of the Gaza Strip and displacing millions of Palestinians were immediately dismissed by many as reckless and half-baked pronouncements, a provocative threat that Mr. Trump was unlikely to enforce.

At the same time, his comments are the latest example of how government officials on the right in both the United States and Israel now speak publicly about a shared goal: the takeover of Palestinian land.

The question of whether the West Bank and the Gaza Strip — territories captured and occupied by Israel in 1967 — might become the foundation of a future Palestinian state has been at the center of decades of failed diplomacy, bedeviling American presidents, Palestinian leaders and Israeli prime ministers.

While the prospects for this future dimmed long ago, Mr. Trump’s election has newly emboldened right-wing ministers in Prime Minister Benjamin Netanyahu’s government, and some of Mr. Trump’s own appointees, to speak publicly about Israel’s right to fully take over the West Bank.

“It’s the most right-wing government that we’ve ever had in Israel — and there never was a U.S. administration that shared these views to this extent, either,” said Itamar Rabinovich, a former Israeli ambassador to Washington.

Days after Mr. Trump’s election, Bezalel Smotrich, Israel’s finance minister, whom Mr. Netanyahu has given broad authority over the West Bank, said Mr. Trump’s return to the White House meant that “the year 2025 will, with God’s help, be the year of sovereignty in Judea and Samaria,” using the biblical name for the territory that makes up the West Bank.

During his news conference with Mr. Netanyahu on Tuesday, Mr. Trump was asked directly whether he supported Israeli annexation of the West Bank. He declined to answer, saying that his administration would have an announcement in “four weeks.”

But he has already appointed at least two people to his administration — Elise Stefanik, his choice to serve as ambassador to the United Nations, and Mike Huckabee, who has been nominated by Mr. Trump to be ambassador to Israel — who hold views similar to Mr. Smotrich and his allies.

During her confirmation hearing, Ms. Stefanik was asked by Senator Chris Van Hollen, Democrat of Maryland, whether she shared Mr. Smotrich’s view that Israel had a biblical right to the entire West Bank.

She said she did.

In an interview, Mr. Van Hollen said that “there is a very dangerous alignment right now” between American and Israeli officials on the issue of Palestinian self-determination.

“Now we have someone in the White House who wants to greenlight the dreams of far-right extremists like Smotrich and Ben-Gvir,” he said, referring to Itamar Ben-Gvir, who recently resigned as Mr. Netanyahu’s national security minister over the cease-fire deal in Gaza.

On his first day in office, Mr. Trump signed an executive order reversing the Biden administration’s sanctions against a group of Israeli settlers responsible for violence and land grabs against Palestinians in the West Bank.

Israeli annexation of the West Bank is a goal shared by both ultranationalists in Israel and many evangelical Christians, including Mr. Huckabee, the former governor of Arkansas, who see the conflict in the Middle East — and the power struggle over the land itself — as a sign of the second coming of Jesus Christ.

Mr. Huckabee has said that “there’s no such thing as a West Bank.” He said that Israeli settlements in the territory, which are considered illegal under international law, are not settlements but “neighborhoods.”

“There’s no such thing as an occupation,” he said during a visit to the West Bank in 2017.

An American or Israeli takeover of Palestinian land would all but scuttle the chances of another diplomatic prize that Mr. Trump said he seeks: the normalization of diplomatic relations between Israel and Saudi Arabia. The Saudi government has said that Israel must take concrete steps toward an independent Palestinian state if there is any chance for the kingdom to officially recognize Israel.

Hours after Mr. Trump’s news conference, the Saudi foreign ministry issued a statement saying that “the establishment of the Palestinian state is a firm, unwavering position” of the kingdom.

With Mr. Trump’s ambitions for the region in possible conflict, Mr. Rabinovich, the former Israeli ambassador, said he thought the president could ultimately be persuaded to block an Israeli push toward West Bank annexation.

“If he wants a Saudi deal, then he won’t go along with annexation,” Mr. Rabinovich said.

Since returning to office in 2022, Mr. Netanyahu has become increasingly blunt about his opposition to Palestinian sovereignty. After years of equivocating on the issue, he boasted last year that “my insistence is what has prevented, over the years, the establishment of a Palestinian state that would have constituted an existential danger to Israel.”

As his coalition prepared to enter office in December 2022, it issued a declaration of the Jewish people’s “exclusive and inalienable right to all parts of the Land of Israel” and pledged to bolster Jewish settlement in all areas, including the occupied West Bank.

Since then, Mr. Netanyahu has made good on that pledge by granting Mr. Smotrich vast new powers over West Bank governance. Critics denounced the move — which gave Mr. Smotrich, a civilian, authority over matters previously overseen by the military — as a form of de facto annexation.

And Mr. Smotrich himself described the move last year as an attempt to seal Israel’s control over the territory without being accused of formally annexing it.

Analysts see Mr. Netanyahu’s most recent appointments to government as an effort to cement that opportunity. His new ambassador to Washington, Yechiel Leiter, is a West Bank settler who had been a spokesman for the settler movement.

Caroline Glick, an adviser to Mr. Netanyahu appointed in recent days who accompanied the prime minister to Washington this week, has long pushed for Israel to annex the West Bank and rejects Palestinian statehood.

And, even though he recently left Mr. Netanyahu’s government, Mr. Ben-Gvir remains an influential voice among the prime minister’s supporters. Shortly after Mr. Trump’s statements on Tuesday, Mr. Ben-Gvir took to social media to give his enthusiastic support.

“Donald, this looks like the beginning of a beautiful friendship,” he wrote.

When Andreas Fichtner unspooled a fiber-optic cable into a deep hole in Greenland’s ice, he wasn’t expecting to discover a whole new way that glaciers move. Even when the cable started sending back data, his first reaction was skeptical.

“Rubbish,” Dr. Fichtner, a professor of seismology and wave physics at the Swiss university ETH Zurich, remembers thinking. “Just some electronic noise.”

This was August 2022. The field season in Greenland was almost over. The cold, the altitude, the long hours — all of it was wearing on Dr. Fichtner and his fellow researchers. But they’d been saving one of their cables for one last experiment, one that would let them measure tiny movements deep within the vast river of ice as it flowed toward the sea.

What they found raises questions about scientists’ assumptions about how the ice sheets of Greenland and Antarctica are moving and adding to sea levels worldwide.

That last cable picked up cascades of tiny “ice quakes,” some of them reverberating hundreds of feet, Dr. Fichtner and his colleagues reported on Thursday in the journal Science.

These quakes seemed to start near impurities in the ice that were deposited by volcanic eruptions, Dr. Fichtner said. Where these particles sit, the ice is weaker, more prone to cracking. Along these cracks, the ice sticks and slips and quivers as it moves, creating tiny seismic disturbances.

This isn’t what scientists usually imagine is going on inside the deep piles of ice that cover Earth’s polar regions. Typically, they think of this ice as flowing like syrup: slowly, smoothly, fluidly.

But if the ice were really moving like a uniform mass of honey, then Dr. Fichtner’s cable would have picked up “complete silence,” he said. Instead, it recorded these “really, really curious events,” he said. “That was the surprise here.”

By sending laser pulses through fiber-optic cable and measuring how they scatter, scientists can reconstruct fine movements along the cable’s entire length. This has proved useful for monitoring seismic activity, deep-sea currents, glacial ice and more.

In Greenland, Dr. Fichtner and a colleague lowered a cable by hand nearly a mile down a borehole, one that other scientists had drilled to extract an ice core. There the cable lay for 14 hours, picking up vibrations.

If winding and unwinding a cable doesn’t sound especially challenging, let Dr. Fichtner be the first to inform you: It was “serious physical work.” The borehole was filled with a special kind of vegetable oil to keep it from closing up, so the cable was slow to sink and heavy to lift back out. Plus, the subzero cold made the cable brittle, meaning they had to handle it with utmost care.

When Dr. Fichtner started looking at the readings that came back, he had to convince himself they weren’t “rubbish.” What if they showed vibrations coming from within the cable itself? Or from cracks forming in the borehole wall?

In time, he and his team concluded that they’d recorded something intrinsic to the ice. Still, Dr. Fichtner acknowledged that only by making more measurements in more places can scientists really say how commonly these quakes occur within ice sheets.

Getting enough measurements is a constant challenge for polar scientists, said Hélène Seroussi, an engineering professor at Dartmouth College in New Hampshire who wasn’t involved in the new research. When oceanographers want to collect data, they can drop instruments into the deep sea in a matter of hours. Glacier researchers have to drill deep into the ice, which takes months, even years.

“That’s why we keep finding all these new principles and mechanisms that seem relatively fundamental,” Dr. Seroussi said. “Each time you have a new observation, a new ice core, a new way of measuring, you learn something new.”

Andy Aschwanden, a glaciologist at the University of Alaska Fairbanks, said Dr. Fichtner and his colleagues’ discovery offered an interesting glimpse into the intricacies of ice physics. But he said it was too early to know whether it can help scientists better predict how quickly the melting ice sheets will lift global sea levels. The ice still holds other mysteries that, if unraveled, are likely to improve the modeling much more, Dr. Aschwanden said.

The new findings could someday help scientists better understand the way ice sheets break apart at their edges, said Richard B. Alley, a professor of geosciences at the Pennsylvania State University.

Pre-existing flaws or damage in the ice can cause it to crack up rapidly once it flows off the land and out to sea, Dr. Alley said. It’s the same reason a fast-food ketchup packet is easy to open if you do it from the little notch, but very difficult if you try to tear it anywhere else, he said.

“All of us who study ice,” Dr. Alley said, “will be building on this new paper for a long time to come.”

For decades, successive presidents in Washington have favored some version of a two-state solution for the Israeli-Palestinian conflict. What no one imagined until now was that the second state would be American, not Palestinian.

President Trump’s stunning plan to displace the entire Palestinian population of Gaza and have the United States take over the seaside enclave has not only convulsed the Middle East. It may have also all but written the obituary for the long-sought but maddeningly elusive goal of establishing a Palestinian state alongside Israel in peaceful coexistence.

Any vision of a Palestinian state has included Gaza as an integral part of it, along with the West Bank. In Mr. Trump’s vision, however, Gaza would become a U.S. territory transformed into a “Riviera of the Middle East.” It would not belong to the Palestinians anymore but would be open to anyone who wanted to live there. And for that matter, he signaled openness to Israeli annexation of parts of the West Bank, promising to reveal his position within four weeks.

The prospects for a Palestinian state had already dwindled in recent years, especially after the Hamas terrorist attack on Israel on Oct. 7, 2023, that killed 1,200 people and led to the Israeli retaliatory war in Gaza that has killed 47,000 combatants and civilians, according to Gaza health authorities. Neither Israeli nor Palestinian populations see the two-state scenario as a viable plan anymore, according to polls.

But the rest of the world, led until now by the United States, has continued to cling to the idea as official policy, if for no other reason than a lack of alternatives. And Saudi Arabia has insisted that a Palestinian state has to be part of any deal establishing diplomatic relations with Israel, a goal avidly pursued by both Mr. Trump and former President Joseph R. Biden Jr.

“If Trump thinks that somehow the U.S. owning Gaza and allowing Israel to annex parts of the West Bank facilitates a deal, he’s completely wrong about that,” said Jeremy Ben-Ami, president of J Street, a liberal, pro-Israel, Washington-based organization that promotes a negotiated peace in the Middle East. “There’s no way forward to a deal.”

But opponents of a Palestinian state feel emboldened at this point. While few took Mr. Biden’s continued insistence on the two-state solution all that seriously, they feel confident that Mr. Trump’s return to power means that there will never be a Palestinian state.

“It’s a dead issue,” said Morton A. Klein, national president of the Zionist Organization of America, which opposes the two-state solution. “I think most people think it’s a dead issue.” He added: “They had a state in Gaza. How did that work?”

Mr. Trump has long cast himself as the one person who could bring peace to the Middle East — just Thursday, he told an audience at the National Prayer Breakfast that he wanted to be remembered as “a peacemaker” — but he has never achieved his own aspiration. When he took office in 2017, he took on the mission of finally resolving the generations-old conflict between the Israelis and Palestinians, boldly predicting that it would be “not as difficult as people have thought over the years.”

But it turned out to be just as difficult as people have thought over the years. He assigned his son-in-law Jared Kushner to develop a plan that was released in 2020 that envisioned a Palestinian state of sorts, but one so truncated that the proposal was widely seen as tilted toward Israel. Under the plan, Israel would have been allowed to keep its settlements in the West Bank and full control of a unified Jerusalem as its capital, while the Palestinians would have been offered $50 billion in international investment.

The plan went nowhere, but Mr. Trump was able to score a consolation prize by presiding over the establishment of diplomatic relations between Israel and several Arab states, including Bahrain and the United Arab Emirates, in what was called the Abraham Accords.

Saudi Arabia declined to join at the time, but Mr. Biden came close to securing a deal until the Oct. 7 attack blew up the negotiations. Now back in office, Mr. Trump hopes to finalize such an agreement, which would help transform the region.

But he has made no recommitment to a two-state solution since returning to power and his newly designated ambassador to Israel, Mike Huckabee, all but ruled it out. “I’d be very surprised if he comes and says, ‘Let’s go out there and get a two-state solution,’” Mr. Huckabee said last month in an interview with Ami Magazine, a Jewish magazine based in New York.

Mr. Trump remained ambiguous about that this week. When he announced his plan to take “ownership” over Gaza at a White House news conference with Prime Minister Benjamin Netanyahu of Israel, he was asked if that meant he no longer supported the two-state solution. “It doesn’t mean anything about a two-state or a one-state or any other state,” he replied. “It means that we want to have — we want to give people a chance at life.”

Asked about that the next day on CBS News, Mr. Trump’s national security adviser, Mike Waltz said, “I certainly didn’t hear the president say it was the end of the two-state solution.” But neither he nor any other administration officials have explained how taking Gaza away from the Palestinians could be reconciled with establishing a state that would be acceptable to them.

The reaction to Mr. Trump’s Gaza plan was broadly negative outside Israel. In the past couple of days, António Guterres, the United Nations secretary general, as well as leaders from Saudi Arabia, Egypt, Jordan, Britain, France, Germany, Australia, Turkey, Canada, Japan, the European Union and others all restated support for the two-state solution. “There is only one solution and that is a two-state solution,” Foreign Minister Lars Lokke Rasmussen of Denmark told Danish media.

But at some point, that came across more as a diplomatic ritual of talking points than a realistic agenda. In Israel and the Palestinian territories, the notion of two states living side by side in peace has lost the broad support it once had.

In Israel, just 27 percent of people still backed a two-state solution in Gallup polling last summer, while 64 percent opposed it. That was a reversal from 2012, when 61 percent supported it and just 30 percent opposed it.

And that was almost identical to the views of Palestinians in the West Bank and East Jerusalem, where just 28 percent of those interviewed last summer supported such a plan, while 64 percent opposed it. That too represented a radical drop in enthusiasm from 2012, when 66 percent in those areas supported it compared with 32 percent who did not.

Yaakov Amidror, a former national security adviser to Mr. Netanyahu, said that the two-state solution as long conceived was dead.

“There is no way to rebuild Gaza,” he told Al Arabiya television. “The West Bank is another political issue to be discussed. But in Gaza, I don’t see two million Palestinians living in less than 400 square kilometers in which 80 percent of the buildings have been destroyed.”

Elliott Abrams, who has advised multiple Republican presidents on the Middle East, including Mr. Trump during his first term, said the reality is that a two-state solution has not been viable for quite some time even if world leaders refuse to accept that. While the president’s Gaza takeover plan may itself be untenable, Mr. Abrams said it focused on the plight of Palestinians living in an area devastated by war rather than lines on a map.

“Trump’s plan changed the subject from politics to what happens to the people,” Mr. Abrams said. “He spoke about how Gazans live now, and could live so much better in the future, and he did not demonize Gazans. So his plan is a reminder that the two-state solution is just foreign ministers shouting at each other, and it’s no solution at all.”

From the other side of the debate, Mr. Ben-Ami agreed that Mr. Trump had a point. “There is an element of truth underneath all this, which is that it’s really hard to conceive how you would rebuild with two million people still there,” he said.

He also agreed that “the concept of an old-fashioned two-state solution has actually been gone for a while.” But he held out hope that it would still be part of a broader, regionwide change driven by Arab rapprochement with Israel, led by Saudi Arabia. “It’s going to have to be part of that normalization deal,” Mr. Ben-Ami said. “We’ve been referring to it as a 23-state solution.”