Trump must ensure there are consequences for supporting U.N. Security Council Resolution 2334.

Last Friday, on the eve of Hanukkah and Christmas, Barack Obama stabbed Israel in the front. The departing president refused to veto United Nations Security Council Resolution 2334—a measure ostensibly about Israeli settlement policy, but clearly intended to tip the peace process toward the Palestinians. Its adoption wasn’t pretty. But, sadly, it was predictable. Mr. Obama’s refusal to use Washington’s veto was more than a graceless parting gesture. Its consequences pose major challenges for American interests. President-elect Donald Trump should echo Ambassador Daniel Patrick Moynihan’s defiant and ringing 1975 response to the U.N.’s “Zionism is racism” resolution: that America “does not acknowledge, it will not abide by, it will never acquiesce in this infamous act.” Mr. Obama argues that Resolution 2334 continues a bipartisan American policy toward the Middle East. It does precisely the opposite. The White House has abandoned any pretense that the actual parties to the conflict must resolve their differences. Instead, the president has essentially endorsed the Palestinian politico-legal narrative about territory formerly under League of Nations’ mandate, but not already under Israeli control after the 1948-49 war of independence. Resolution 2334 implicitly repeals the iconic Resolution 242, which affirmed, in the wake of the 1967 Six-Day War, that all affected nations, obviously including Israel, had a “right to live in peace within secure and recognized boundaries free from threats or acts of force.” It provided further that Israel should withdraw “from territories occupied in the recent conflict”—but did not require withdrawal from “the” or “all” territories, thereby countenancing less-than-total withdrawal. In this way Resolution 242 embodied the “land for peace” theory central to America’s policy in the Middle East ever since. By contrast, Resolution 2334 refuses to “recognize any changes to the [1967] lines, including those with regard to Jerusalem, other than those agreed by the parties through negotiations.” This language effectively defines Israel’s borders, even while superficially affirming direct talks. Chatter about Israeli-Palestinian negotiations is nothing but a truism, equally applicable to the U.S. and Canada, or to any nations resolving trivial border disputes.

The Trump administration could veto future Security Council measures that extend Resolution 2334 (e.g., purportedly recognizing a Palestinian state). Mr. Trump could also veto efforts to implement Resolution 2334 (e.g., the sanctions for what it calls Israel’s “blatant violation under international law”). Still, there are significant dangers. Other U.N. bodies, such as the General Assembly and the numerous specialized agencies where America has no veto, can carry Resolution 2334 forward. Even more perilous is that individual nations or the European Union can legislate their own sanctions under Resolution 2334’s provision that “all States” should “distinguish in their relevant dealings” between Israel’s territory “and the territories occupied since 1967.” This is a hunting license to ostracize Israel from the international economic system, exposing it and its citizens to incalculable personal and financial risk. Once in office, President Trump should act urgently to mitigate or reverse Resolution 2334’s consequences. Mr. Obama has made this significantly harder by rendering America complicit in assaulting Israel. Nonetheless, handled properly, there is an escape from both the current danger zone and the wasteland in which the search for Middle East peace has long wandered. First, there must be consequences for the adoption of Resolution 2334. The Trump administration should move to repeal the resolution, giving the 14 countries that supported it a chance to correct their error. Nations that affirm their votes should have their relations with Washington adjusted accordingly.

As for the United Nations itself, if this mistake is not fixed the U.S. should withhold at least its assessed contributions to the U.N.—which amount to about $3 billion annually or 22%-25% of its total regular and peacekeeping budgets.

Second, Mr. Trump should unambiguously reject Mr. Obama’s view that Resolution 2334 is justified to save the “two-state solution.” That goal, at best, has been on life-support for years.

Far better to essay a “three-state solution,” returning Gaza to Egypt and giving those parts of the West Bank that Israel is prepared to cede to Jordan. By attaching Palestinian lands to real economies (not a make-believe one), average Palestinians (not their political elite), will have a true chance for a better future. Other alternatives to the two-state approach should also be considered. Mr. Obama loves using the word “pivot” for his ever-changing priorities. It is now up to Mr. Trump to pivot away from his predecessor’s disastrous policies on Israel. Taking up the challenge will be difficult, but well worth the effort for America and its friends world-wide.

More From The Wall Street Journal (subscription required):