A family washes clothes outside the cave they use as their home on the outskirts of the West Bank village of Mufagra. (Abed Al Hashlamoun/European Pressphoto Agency)

Stuart E. Eizenstat is a former ambassador to the European Union and deputy treasury secretary in the Clinton administration, where he headed the economic dimensions of the Middle East peace process. Dennis Ross, a counselor at the Washington Institute for Near East Policy, was a special assistant to President Obama from 2009 to 2011.

We have long worked to promote peace between Israelis and Palestinians, believing that with two national movements, the only realistic answer is two states for two peoples. Unfortunately, this objective has never been less attainable. We believe, therefore, that it is time for a Plan B — an approach that incoming president Donald Trump might broker.

Ironically, the ill-conceived and deeply flawed U.N. Security Council resolution condemning Israeli settlement activity has made a Plan B even more necessary. By declaring all settlements “a flagrant violation under international law,” the resolution undercut the sole formula that stands a chance at some point of reconciling Israeli and Palestinian needs on final borders — accepting settlement blocs and engaging in territorial swaps. Instead, it has hardened positions on both sides.

Even without this counterproductive resolution, realities on the ground and political and psychological gaps between Israelis and Palestinians make a comprehensive two-state peace agreement illusory at this time. But doing nothing is a prescription for drifting toward a one-state outcome, a result that, due to demographics, would mean Israel over time would become a binational state and no longer majority-Jewish and democratic. Our Plan B would promote peaceful coexistence through practical steps that restore shattered trust on both sides, protecting Israel’s security while creating a more prosperous and less resentful and violence-prone Palestinian population. Plan B can help resolve the dilemma facing Israel, a high-tech wonder thoroughly integrated into the global economy but more politically isolated than ever. Meanwhile, it could provide Palestinians more living space for development, reduce incentives for Palestinian violence and help preserve effective counterterrorism cooperation between Israeli and Palestinian security forces.

The start lies in a new vision for Israel’s West Bank settlements, formally recognizing that not all settlements are the same when it comes to preserving a two-state outcome. They would continue to be protected by the Israeli military; there would be no unilateral withdrawals, as disastrously occurred in Gaza; and three major new sections of the incomplete security fence would be built to block infiltration by terrorists.

To reduce tensions with Israel, building could continue unabated within the three major settlement blocs near the pre-1967 Green Line, where over 8 in 10 of all settlers live on less than 5 percent of the West Bank. These blocs are consistent with a two-state outcome and in a final settlement would become part of Israel, with other land within Israel swapped and becoming part of the Palestinian state.

But settlement expansion would cease in those areas outside the blocs in what could eventually become a demilitarized Palestinian state. No hilltop and other outposts, now illegal under Israeli law, would be legalized retroactively, and strict rule of law would be observed to prevent construction on Palestinian private land and to preserve the option of a Palestinian state with contiguous territory. While politically difficult for Prime Minister Benjamin Netanyahu given his current coalition, his “hard-line” defense minister, Avigdor Lieberman, has come out in favor of reaching an agreement with the Trump administration allowing Israel to build within the blocs but not outside them. Under Netanyahu, only a small percentage of settlement expansion has occurred in these isolated settlements during the Obama years.

The other centerpiece of Plan B would be empowering the Palestinian economy through the kind of private-sector development the Trump administration should like, rather than sending more U.S. aid to the Palestinian Authority. The 1995 Oslo Interim Agreement divided the West Bank into three areas, in two of which the overwhelming majority of the 2.7 million Palestinians live with no Israeli settlements, and only in the largest of which, Area C, the Israelis retain complete control.

Today, Area C is 60 percent of the West Bank and contains almost all of the West Bank’s natural resources and agricultural land. The key to economic advancement for the Palestinians lies in their residential, commercial, agricultural and industrial development, none of which is now allowed without Israeli permits, which are almost never granted. Palestinian access to land, water, electricity, education, health services, bank branches and even ATMs is very limited, while Israeli settlers benefit from all of these and even have their own roads. At a time when the Israeli economy continues to grow healthily, small wonder the Palestinian economy is in shambles, with high rates of unemployment.

There should be broad Israeli political support for taking concrete steps to improve these dire conditions by increasing the number of Palestinians working in day jobs in Israel, thereby reducing the 50,000 illegal Palestinian workers and increasing remittances that could be invested in the West Bank. Building permits in Area C could be vastly expanded, along with greater access to water, electricity and other essential services for Palestinians throughout the West Bank, spurring development. Israeli and Palestinian banks could be connected through the SWIFT interbank system.

The World Bank estimates these steps could add 35 percent to the Palestinian gross domestic product and increase Palestinian jobs by an equivalent amount. In addition, U.S.-supported Qualifying Industrial Zones allow products with at least 10 percent Israeli content to come to the U.S. duty-free: These exist in Jordan and Egypt and could be established in the West Bank to foster Israeli-Palestinian business cooperation and create employment.

Plan B is not a substitute for a political outcome; it is designed to change conditions so that meaningful negotiations not feasible today might become possible over time, while reducing tensions in the meantime. By starting with Plan B, the next president could pave the way later on for the ultimate, elusive deal.