In a letter to Israeli Prime Minister Benjamin Netanyahu and Defense Minister Benny Gantz on Thursday, 18 Senate Democrats warned that such a move would mark a dramatic reversal of decades of shared understandings between the United States, Israel, the Palestinians, and the international community, and would impact Israel’s future, placing its security and democracy at risk, murphy.senate.gov reported.

A deep commitment to Israel’s security and a shared set of democratic values are foundational elements of the close relationship between the US and Israel, they wrote.

“We are therefore concerned that unilateral annexation puts both Israel’s security and democracy at risk. Annexation would betray our shared democratic values by denying Palestinians’ right to self-determination in a viable, sovereign, independent, and contiguous state. It could bring an end to Palestinian security cooperation with Israel, directly threatening the security of the Israeli people, and endanger Israel’s crucial peace agreement with Jordan,” the senators wrote.

The senators concluded: “As friends and supporters of Israel, we caution you against taking unilateral steps that would fray our unique bonds, imperil Israel’s future and place out of reach the prospect of lasting peace. If you move forward with unilateral annexation, we would not support that action. This is consistent with long-standing American policy opposing unilateral actions by either party to the conflict. The pursuit of a viable, negotiated two-state solution is essential to ensuring our shared democratic values and lasting bipartisan support for Israel in Congress.”

Joining Murphy, Kaine and Van Hollen were Senators Brian Schatz, Patrick Leahy, Dick Durbin, Sherrod Brown, Tammy Baldwin, Tom Udall, Jeff Merkley, Ed Markey, Martin Heinrich, Sheldon Whitehouse, Jeanne Shaheen, Tammy Duckworth, Tom Carper, Elizabeth Warren, and Bernie Sanders.

In a speech late Tuesday, Palestinian President Mahmoud Abbas declared an end to security cooperation with Israel and the United States, citing the imminent threat of Israeli annexation of parts of the West Bank.

Abbas said the annexation plans showed Israel was no longer abiding by peace accords between the two.

A genuine end to security coordination could jeopardize the relative calm in the West Bank, where 2.7 million Palestinians and more than 400,000 Israeli settlers live.

Israel controls all access to the territory where Abbas’s government is based.

The declaration came as international opposition to the Israeli plans of annexations in the occupied West Bank grows.

US Democratic presumed presidential nominee Joe Biden on Tuesday became the latest high-profile figure to oppose Netanyahu’s plan to apply Israeli sovereignty to settlements and the strategic Jordan Valley, which makes up around 30 percent of the West Bank.

Palestinians say any annexation would put an end to their hopes of an independent state, the so-called two-state solution.