Countering Republican criticism, Secretary of State John Kerry declared Thursday it is “fantasy plain and simple” to claim that President Barack Obama failed to insist on enough restraints on Iran’s nuclear program before agreeing to lift economic sanctions long in place.

“So what’s your plan? … Totally go to war?” he challenged lawmakers who want to torpedo the deal.

Republicans were unpersuaded — and said so — at an occasionally contentious Senate Foreign Relations Committee hearing that marked the opening of a new phase in the administration’s drive to prevent Congress from undermining the accord.

“You guys have been bamboozled,” said Sen. Jim Risch, R-Idaho, complaining that the agreement wouldn’t permit neutral testing at Iran’s Parchin military complex to guard against cheating.

Sen. Bob Corker, R-Tenn., the panel’s chairman, told Kerry moments after opening the hearing, “Not unlike a hotel guest that leaves only with a hotel bathrobe on his back, I believe you’ve been fleeced.” He later sought to soften the criticism to avoid singling anyone out, saying, “We’ve been fleeced.”

The deal, reached earlier this month, will take effect unless Congress blocks it. Republicans in control of the House and Senate hope to do that by passing legislation in September to prevent Obama from lifting sanctions that lawmakers put in place over several years.

Obama, who met at the White House during the day with a group of House Democrats, has promised to veto any such bill. That would lead to a vote to override his veto, and the administration is searching for 34 votes in the Senate or 146 in the House to assure a veto would stick.

Democrats and allied independents control 46 seats in the Senate, and so far Sens. Dick Durbin of Illinois, Dianne Feinstein of California and Martin Heinrich of New Mexico have announced support for the plan. In the House, Democratic Leader Nancy Pelosi has expressed optimism that a veto can be upheld.

The hearing unfolded as House Speaker John Boehner hinted at additional steps to stop the deal beyond the legislation, which is expected to be voted on after lawmakers return from an August vacation. “I think there’s a lot of tools at our disposal,” he told reporters, although he did not elaborate.

Given the political calculus, the Senate hearing wasn’t so much an attempt by Kerry to persuade Republicans to support the plan as it was an opportunity to reassure Democrats.

Even so, no matter the objections — and Republicans leveled many in a hearing that stretched until midafternoon — Kerry, Energy Secretary Ernest Moniz and Treasury Secretary Jack Lew were ready with responses.

Kerry read supportive comments from former Israeli intelligence officials who hold views diametrically opposed to the ones held by Prime Minister Benyamin Netanyahu’s, arguably the pact’s fiercest opponent.

He also said he expects support for the deal from Saudi Arabia, Iran’s rival in the Middle East. Half a world away, by coincidence or not, Foreign Minister Adel al-Jubeir said the agreement appears to have the provisions needed to curtail Iran’s ability to obtain a nuclear weapon. Saudi Arabia and Iran are fierce rivals, and al-Jubeir met separately with Kerry and Obama last week.

When Sen. Marco Rubio of Florida, a Republican presidential hopeful, asked a question suggesting the deal would require the United States to support Iran if Israel launches a military strike, Moniz had a one word answer: “No.”

“It does not?” Rubio asked skeptically.

“No,” said Moniz.

With the exception of Sen. Bob Menendez of New Jersey, Democrats questioned administration officials far more gently than the Republicans, suggesting they will side with Obama on a deal he has called historic.

At its heart, the agreement calls for the United States and other world powers to end economic and military sanctions in exchange for concessions from Iran in its nuclear program. Tehran says its program is entirely peaceful, but the U.S. and most other nations believe it is aimed at acquiring nuclear weapons. They imposed sanctions on Iran to bring it to the bargaining table.

Across more than four hours in the witness chair, Kerry sought repeatedly to blunt one of the Republicans’ core objections, that Obama settled for a less favorable deal than he could have gotten had he insisted on more.

“The alternative to the deal we’ve reached isn’t what we’re seeing ads for on TV,” he said, referring to commercials backed by the American Israel Public Affairs Committee, which strongly opposes the deal.

“It isn’t a better deal, some sort of unicorn arrangement involving Iran’s complete capitulation. That’s a fantasy, plain and simple.”

Kerry also said that Obama has “made it crystal clear we will never accept a nuclear-armed Iran.” More than that, he said, “he is the only president who has developed a weapon capable of guaranteeing that. And he has not only developed it, he has deployed it.”

That appeared to be a reference to a “bunker buster” bomb, the Massive Ordnance Penetrator.

Kerry said that when the negotiations began, experts calculated that it would take Iran only two to three months to produce enough material for a bomb.

“If the deal is rejected, we return immediately to this reality, except that the diplomatic support we have been steadily accumulating in recent years would disappear overnight,” he said.

(AP)