Nine of our former congressional colleagues joined us last week in announcing our support for the international weapons agreement between the P5+1 nations and Iran. In a full-page ad in The New York Times, we wrote that the joint comprehensive plan of action halts the immediate threat of a nuclear-armed Iran. Rejecting the deal is unlikely to lead to stronger restrictions on the Iranian nuclear program, but would instead leave Iran within two to three months of developing a nuclear weapon.

The 11 of us pointed to Treasury Secretary Jacob J. Lew who has said, the suggestion that a “better deal” can now be obtained “is a dangerous fantasy.”

In our collective declaration of support we noted that under this agreement, the core of Iran’s plutonium reactor at Arak will be removed and filled with concrete, and 98 percent of Iran’s enriched uranium stockpile will be eliminated. Military options also remain on the table should Iran violate the agreement.

In the letter we acknowledge — along with former Sen. Carl Levin and former members of Congress Tony Beilenson, Barney Frank, Sam Gejdenson, Paul Hodes, Elizabeth Holtzman, Steve Kagen, Abner Mikva and Steve Rothman — that many nuclear experts and former military and intelligence officials in both the U.S. and Israel also back this agreement. More than 70 nuclear experts called for approval of the Iran nuclear deal citing it as “strong, long-term and verifiable.”

Three dozen retired U.S. generals and admirals also signed a letter calling the deal “the most effective means currently available to prevent Iran from obtaining nuclear weapons.” Gaining international support for military action against Iran, should that ever become necessary, “would only be possible if we have first given the diplomatic path a chance,” they said. Top Israeli military and intelligence leaders, including dozens of Israeli generals, also have expressed similar assessments, and called for an Israeli policy to “renew the trust between and enhance the political and security cooperation with the U.S.”

Hundreds of American rabbis and more than two dozen of the top Jewish communal leaders of the past few decades also spoke out in support.

Absent this agreement with Iran, the United States’ capacity to closely monitor Iran’s program and detect covert nuclear weapons development will be severely weakened. With the deal, we gain unprecedented, intrusive inspections and around-the-clock monitoring of Iran’s entire nuclear supply chain.

The accord also establishes a powerful snapback mechanism that allows the United States to unilaterally re-impose sanctions if Iran cheats. As our former colleague Rahm Emanuel of Illinois put it: “The alternatives are being the only country standing with a set of sanctions when every international partner that you built painstakingly walks away.”

Former Rep. Jane Harman of California also said, “This deal doesn’t assume that we live in the best of all possible worlds. Instead, it keeps one eye fixed on the doomsday scenario. And in that case, effective diplomacy will have laid the groundwork for effective use of force.”

As members of Congress, those of us who signed the ad championed the U.S.-Israel alliance, unwaveringly supported Israel, led or co-sponsored every major piece of legislation to strengthen the U.S.-Israel relationship and stood at the forefront of every major piece of sanction law designed to halt Iran’s pursuit of nuclear weapons. We remain deeply committed to Israel’s security and survival and continue to work vigorously to strengthen the U.S.-Israel relationship.

The international agreement with Iran is the best available option to prevent Iran from achieving a nuclear weapon. We urge Congress to support the deal.

Robert Wexler served as a Democrat in the House of Representatives from Florida from 1997 to 2010, and is now president of the S. Daniel Abraham Center for Middle East Peace. Mel Levine was a Democratic member of Congress from California from 1983 to 1993 and is now a member of the board of directors of the Pacific Council on International Policy.