The Trump administration’s reported plan to redefine who it considers a Palestinian refugee may further decrease its influence in the peace process.

The Trump administration is reportedly ending all funding to the United Nations Relief and Works Agency for Palestine Refugees in the Near East (UNRWA) and calling for a dramatic change in how Palestinian refugees are counted, effectively reducing the number of Palestinians the United States considers refugees from around 5 million to fewer than 500,000, The Washington Post reported.

What this effectively does is end for most Palestinians the UN-backed “right of return” to land they or their ancestors fled in 1948, when the state of Israel was created, and 1967, when Israel defeated a combined Arab military force in the Six-Day War. (Neither Israel nor the U.S. recognizes the “right of return,” which remains a key sticking point in the peace process.)

Just who counts as a Palestinian refugee is a matter of controversy for the Trump administration and some Israelis. UNRWA counts those Palestinians who were displaced from the region in the 1948 and 1967 wars, as well as their descendants—even if they possess the citizenship of the Arab country to which their ancestors fled—as refugees. This policy has resulted in 5 million Palestinians with refugee status. The Office of the UN High Commissioner for Refugees, the UN refugee agency, on the other hand, counts the world’s other refugees differently: A refugee’s descendant with the citizenship of another country is not considered a refugee. As Jay Sekulow, the president’s counsel, wrote in Foreign Policy, Palestinians are the only class of refugees in the world accorded that status purely because of their descent, adding: “There is no provision for refugee status based on descent in the 1951 refugee convention or in internationally accepted practices for refugees who are not Palestinian refugees.” Some Israelis point out that the potential return of 5 million refugees to Israel would dramatically alter their country’s demographics. Palestinians want the issue to be resolved as part of a final negotiation with Israel on a two-state solution.

U.S. presidential administrations, including this one, have criticized UNRWA as anti-Israeli and have said it needed reform. The United States is the largest contributor to the UNRWA, last year providing about one-quarter of its $1.24 billion budget. Earlier this week, when Nikki Haley, the U.S. ambassador to the UN, was asked at an event in Washington about the possible funding cut to UNRWA, she replied: “First of all, you’re looking at the fact that there’s an endless number of refugees that continue to get assistance. But more importantly, the Palestinians continue to bash America.”

The reported decision to cut funding to UNRWA comes just months after President Donald Trump moved the U.S. Embassy from Tel Aviv to Jerusalem, in line with U.S. law passed in 1995. (Israel regards Jerusalem as its eternal, undivided capital. The Palestinians want East Jerusalem to be the capital of their future state.)

The latest reported move could have significant consequences for the U.S. role in the moribund Mideast peace process. The White House is expected to soon release its own plan for peace in the region, a proposal that is being drafted by Jared Kushner, Trump’s son-in-law who serves as a White House senior adviser, and Jason Greenblatt, the president’s special envoy to the peace process. But the embassy move, combined with the funding for UNRWA, and news last week that the Trump administration was cutting about $200 million in aid for the Palestinians in the West Bank and Gaza, is likely to ensure that the plan is dead on arrival.

“I don’t think there’s a realistic possibility that this peace plan will have traction,” Dave Harden, a former USAID assistant administrator for the region, told me. “We’re less important because we’re not putting money in the game. We’ve already determined our positions on Jerusalem and the Palestinian claim of right of return … We were seen as someone who could at least exert leverage over the Israelis, and I don’t think that the Arab states will see us being central to the outcome.”

Indeed, if Saudi Crown Prince Mohammed bin Salman was seen as being more amenable to a Kushner plan, his father, King Salman, has assured the Palestinians of Arab support. The Trump administration’s decision to move the U.S. Embassy to Jerusalem has had few followers in the international community. Changing how Palestinian refugees are counted might have some supporters in Israel and even some logic to it, but ultimately it is unlikely to make much of a practical difference to the peace process. Michael Koplow, the policy director at the Israel Policy Forum, a think tank that favors a two-state solution, said in an email that the Trump administration appears to be operating under the assumption that changing the definition of who is a Palestinian refugee “will settle the issue in the context of negotiations, but this is unlikely to be the case.” He said that while the move is likely to be welcomed by Israelis, “it is hard to see how it will advance the peace process by even an inch rather than making a permanent status negotiation more difficult.”

The more immediate impact of the U.S. decision is likely to be reduced influence in a process that has seen little movement in years. “We are basically vacating the political space,” said Harden, who is now the managing director of the Georgetown Strategy Group, a consulting firm. “We’re ceding that space to others.” Those others could include the Israeli government and the Palestinian Authority, whose political leaderships mostly snipe at each other these days; Hamas, the militant group that governs Gaza; Russia, whose influence in the Middle East is growing; or the European Union. As Harden put it: “I don’t think that we can know exactly who we’re ceding the space to, but we’re ceding the space.”

Meanwhile, Harden said, “the Palestinians aren’t going away. They’ve lived there for hundreds of years or thousands of years and they’re going to continue to live there. The Israelis and the Palestinians are ultimately going to have to work this out. They’re not getting divorced—and they’re not moving to separate parts of the world.”