WASHINGTON — President Barack Obama on Wednesday defended his controversial nuclear agreement with Iran in the strongest terms yet, warning that critics of the deal — such as groups running television ads in Maryland to sway key Sen. Ben Cardin — are setting the nation up for another war in the Middle East.
Obama called a coming vote in Congress on the agreement the most consequential for U.S. foreign policy since lawmakers authorized the invasion of Iraq more than a decade ago. And he argued, bluntly, that many of the most vocal U.S. critics of the deal are the same people who supported sending America to war in Iraq.
Obama's speech came as another interest group began airing ads on the agreement in Maryland, part of a national campaign to sway undecided Democrats, whose support Obama needs to counter Republican opponents. The television ads in Maryland are aimed at Cardin, the top Democrat on the Senate Foreign Relations Committee and a longtime supporter of Israel.
"Without this deal, the scenarios that critics warn about happening in 15 years could happen six months from now," Obama said in an address at American University. "By killing this deal, Congress would not merely pave Iran's pathway to a bomb, it would accelerate it."
The agreement negotiated last month with five other nations — including Russia, France, the United Kingdom and Germany — requires Iran to dismantle its nuclear program for a decade in exchange for relief from crippling international sanctions.
Supporters and opponents of the deal have been heavily lobbying lawmakers ahead of the August congressional recess. The House and Senate are expected to vote on a Republican resolution to reject the pact next month, setting up a battle over whether Obama can rally enough Democrats to sustain his promised veto.
At several points, Obama sharpened his nearly hourlong speech to a knife's edge. He compared his GOP critics to the zealots in Iran: "It's those hard-liners chanting 'Death to America' who have been most opposed to the deal," he said. "They're making common cause with the Republican caucus."
GOP leaders quickly accused Obama of distorting the facts and using inflammatory language.
Senate Majority Leader Mitch McConnell of Kentucky called on Obama to "retract his bizarre and preposterous comments."
Opponents, including many Republicans in Congress but also prominent Jewish groups, say that the agreement will allow Iran to rebuild its nuclear capability after its 10-year window and that Tehran will use the billions of dollars it receives from lifted sanctions to fund terrorism and destabilize the Middle East.
"Contrary to what President Obama's administration has said, this deal is in no way 'pro-Israel,'" said Rep. Andy Harris, Maryland's only Republican in Congress. "I continue to believe that all efforts should be made to prevent Iran from acquiring nuclear weapons capabilities."
J Street, a left-leaning Jewish group that describes itself as pro-Israel and pro-peace, began a $245,000 ad campaign in Baltimore on Wednesday in support of the deal, which it calls "good for Israel, good for America and makes both countries safer."
The advertisement follows TV spots from opponents of the deal, including Citizens for a Nuclear Free Iran — a nonprofit formed by the American Israel Public Affairs Committee — and American Security Initiative, which was created by three former senators, Republicans Saxby Chambliss of Georgia and Norm Coleman of Minnesota, and Democrat Evan Bayh of Indiana.
"Iran has violated 20 international agreements," the narrator says in the ad by Citizens for a Nuclear Free Iran. "Congress should reject a bad deal."
The outside advertising is working its way into key states represented by powerful but undecided Democrats. Given his close relationship with the White House and his long support of Israel, Cardin's decision is likely to influence others and send a signal about how much support the administration can expect from its own party.
Cardin has not announced a position.
"I agree with the president that this is a pretty consequential vote," he said in a statement. "At the end of the day, it is not what is popular, and not what the President of the United States wants us to do, but what is best for our country."
The president met privately with Jewish leaders at the White House on Tuesday and said he would be diplomatic in his address. As he put the speech together, however, White House aides say he articulated a different priority, to be perfectly clear about what he believes is at stake.
Obama said the U.S. must "take seriously" concerns raised by Israel, but he directly took on Israeli Prime Minister Benjamin Netanyahu, who has strenuously opposed it.
"I recognize that Prime Minister Netanyahu disagrees — disagrees strongly," Obama said. "I do not doubt his sincerity. But I believe he is wrong. I believe the facts support this deal."
A nuclear-armed Iran, Obama said, "is far more dangerous to Israel, to America, and to the world than an Iran that benefits from sanctions relief."
Obama repeatedly invoked gauzy images of Presidents John F. Kennedy and Ronald Reagan as bipartisan models for negotiating with a sworn adversary, citing their nuclear arms control deals with the Soviet Union.
The location of the address was a further allusion: Kennedy used a speech at American University 52 years ago to announce the first nuclear test ban treaty negotiations with the Soviet Union.
Arthur C. Abramson, executive director of the Baltimore Jewish Council, described Obama's speech as "impressive" but said it did not change his opposition to the deal.
"He did as good a job as anybody could possibly do in terms of arguing why it needs to be approved," Abramson said.
The influential council issued a lengthy statement last week urging Obama to drop the agreement and "negotiate a better deal."
The problem, Abramson said, is that Iran cannot be trusted to uphold its commitments. It's not clear, he said, whether the concept of mutually assured destruction that served as a deterrent to the use of nuclear weapons during the Cold War — and allowed Kennedy and Reagan to make diplomatic progress — is an adequate measure of prevention for Iran.
"If we were talking about a rational perspective on international relations … I could easily see the case for, 'well, let's give Iran a chance,'" Abramson said. "In this particular instance — and this is a big problem — you are not necessarily dealing with a rational regime."
Tribune Newspapers' Washington bureau contributed to this article.