President Obama is rumored to be considering a major reversal of decades-long U.S. policy toward Israel by supporting a UN Security Council resolution that unilaterally recognizes a Palestinian state before a peace agreement is negotiated between Israel and the Palestinians. Congress must act to counter this bold and reckless move that endangers Israel’s security and America’s strategic interests.

There is much at stake: Israel is a free and democratic ally in a hostile region that has been repeatedly attacked by its neighbors. Before it occupied the West Bank, Gaza, and Golan Heights in 1967, these territories were used as a base of war and terrorism against the Jewish state. Offers to create a Palestinian state in Gaza and most of the West Bank that would allow for a safe and secure Israel have been repaid by intifada after intifada.

Others have argued persuasively that any Palestinian state established in the absence of a peace agreement with Israel will become a virtually ungovernable hotbed of terrorism sure to threaten not just Israel, but also the region and the world. The events in Gaza in the past decade strongly support this position. Ordinary Palestinians will also suffer, forced to endure rule by the same Islamic fanatics and brutal, corrupt autocrats who have destroyed their economy.

A White House decision to support unilateral Palestinian statehood would unquestionably be contrary to the will of Congress: 88 senators recently signed a letter opposing such an action, while 388 members of the House have signed a similar letter supporting a veto of all “one-sided” UN resolutions concerning the Israel/Palestine issue.

And these numbers understate congressional opposition: several senators refused to sign the letter because they thought it was insufficiently strong. Furthermore, a White House reversal on unilateral Palestinian statehood would also be contrary to the stated policies of both the Democratic and Republican presidential nominees.

To dissuade a determined White House from this course of action, Congress will have to do more than write letters. Here are some of the legislative options that could throw significant roadblocks in its path.

First, Congress should make clear its intention to sanction any unilaterally-declared Palestinian state and its new leaders, blocking their access to U.S. banking and markets, similar to sanctions on the Iranian regime. Loss of access to the U.S. financial system would be extremely costly to any Palestinian regime.

Second, Congress should make clear its intention to immediately and completely cut hundreds of millions of dollars in annual U.S. direct aid to the Palestinian Authority (PA) in the event that President Mahmoud Abbas succeeds in his bid to win Palestinian statehood recognition at the UN. Congress reduced this aid by 22 percent last year in retaliation for the PA’s continuing terrorism incitement. It would be a significant blow to a new state to cut all such aid.

Third, Congress should mandate that any newly-created Palestinian state be designated a state sponsor of terrorism. This designation would include restrictions on U.S. foreign assistance; a ban on defense exports and sales; and various other restrictions. The Palestinian Authority (PA) currently uses a shell-game to pay the families of terrorists, something Congress is currently working to stop. Other PA ties to various terrorist activities go back decades.

Finally, Congress should review and update decades-old federal laws prohibiting U.S. funding of any UN organization that “accords the Palestine Liberation Organization the same standing as member states” to ensure that they apply and cannot be skirted if Abbas wins Security Council recognition of Palestinian statehood.

Congress should use its power boldly to exert influence over this vital issue. Large majorities in Congress opposed the Iran nuclear deal and had both the facts and public opinion on their side. But due to the peculiarities of the law and the politics of the situation, they were outmaneuvered. Congress should work to ensure this situation is not repeated.

Though knowledgeable and trusted congressional leaders like Senators Arthur Vandenberg and Henry “Scoop” Jackson once led coalitions in Congress that held great influence in foreign affairs, there is a bipartisan belief that Congress has shirked its duty to shape foreign policy in recent decades. Now would be a good time to start taking it back.