By Amy Goodman & Denis Moynihan

A war with Iran would be a catastrophe, yet by opposing diplomacy, hundreds of members of Congress may be blundering into just such a conflict. The Iran nuclear deal, as the complex diplomatic arrangement is popularly called, was agreed upon on July 14 by a consortium of key powerful countries, the European Union and Iran. The goal of the agreement is to limit Iran’s nuclear activities to peaceful purposes, and to block Iran’s ability to construct a nuclear bomb. Despite what its critics say, this agreement is not based on trust. It grants the International Atomic Energy Agency the power to conduct widespread, intrusive inspections to ensure that Iran keeps its many pledges. In return, many, but not all, of the sanctions on Iran, which have been crippling its economy, will be lifted.

The alternative to diplomacy is to pour gasoline on a region of the world already on fire with intense, complex military conflicts. Iran’s military has more than half a million soldiers, no doubt with many more who could be mobilized if threatened with invasion. Iran shares a vast border to its west with Iraq, and to its east with Afghanistan, two nations with ongoing military and humanitarian disasters that have consumed the U.S. military since 2001, costing trillions of dollars and untold lives.

Gary Sick served on the National Security Council under Presidents Gerald Ford, Jimmy Carter and Ronald Reagan, and was the principal White House aide for Iran during the Iranian Revolution and the hostage crisis, when 52 Americans were held hostage in Iran for 444 days, between 1979 and 1981. “Basically, we’ve had two years of negotiation, which have been remarkably successful and produced something that is complicated but nevertheless solves the problem,” Sick said on the “Democracy Now!” news hour. “If that is turned down by the U.S. Congress, the United States is on its own.”

Sick makes a key point: Even if the U.S. Congress rejects the deal, and, after President Barack Obama vetoes that rejection (which he has promised to do), even if the Senate can then muster the 67 votes needed to overturn his veto, that doesn’t mean that the other signatories to the deal will go along with the rejection. China, France, Russia and the United Kingdom, along with other European Union countries, can accept the terms and remove sanctions on Iran. This would leave the United States isolated and alone (with its Middle East ally, Israel), on a war footing against Iran. “The chance of renegotiating it is very close to zero. As the situation evolves, there’s a very real chance of conflict,” Gary Sick said.

Another supporter of the deal is an American activist who was a prisoner in Iran. Sarah Shourd was held for more than 400 days in Tehran’s notorious Evin Prison, much of that time in solitary confinement. She, Shane Bauer and Josh Fattal were the three American hikers who were arrested by Iranian border guards while hiking in Iraqi Kurdistan back in 2009. Much of the criticism of the current deal centers on its failure to secure the release of four other Americans, three of whom are known to be imprisoned in Iran, among them Washington Post reporter Jason Rezaian. The fourth, Robert Levinson, is believed to be alive, but his whereabouts are unknown.

“Not only does it weaken the hard-liner position in Iran and ease tension between our two countries, it could lead to cooperation to combat ISIS,” Shourd said of the deal on “Democracy Now!.” “I also think that it is good for the Americans that are currently detained there. I think it actually gives the Iranian government less incentive to use hostage taking as a tactic.” When a deal was proposed in 2010, during her imprisonment, Shourd recalled: “I was dancing and laughing in my cell, because I had no doubt in my mind that my release and Shane and Josh’s release would be carefully calibrated with the temperature of U.S.-Iranian relations. So, if the temperature is good, it looks better for the hostages.”

On Wednesday, U.S.-based groups organized more than 225 public demonstrations at the offices of members of Congress, in a “No War With Iran” National Day of Action. Shourd joined scores of other prominent women, among them Gloria Steinem, Alice Walker, Jane Fonda and peace activist Medea Benjamin, under the banner of Codepink, declaring, “Women support the Iran nuclear deal; we say no to war and YES to diplomacy.”

When sealing a nuclear-arms deal with the Soviet Union in 1987, President Reagan repeatedly said, “Trust, but verify,” playing on a Russian proverb. Reagan clearly did not trust the Soviets, so he insisted on a thorough verification process. This deal with Iran has exactly that. Give diplomacy a chance.

Browse the archive of Democracy Now! reports on Iran