Hillary Clinton speaks about the Iran nuclear deal at the Brookings Institution in Washington, D.C., September 9, 2015. NICHOLAS KAMM/AFP/Getty Images

Hillary Clinton has spent the vast majority of her campaign talking about domestic and economic issues. But on Wednesday, she delivered an entire speech on Iran and stressed she is “looking forward to a robust debate about foreign policy in this campaign.”

As Republican candidates Donald Trump and Ted Cruz came to Capitol Hill Wednesday to protest the nuclear deal, Clinton forcefully defended the proposed agreement at the Brookings Institution, working to position herself as the adult in the room.

“Here’s how I see it: Either we move forward on the path of diplomacy and seize this path to block Iran’s path to a nuclear weapon, or we turn down a more dangerous path leading to a far less certain and riskier future,” Clinton said, acknowledging that the deal isn’t perfect. “That’s why I support this deal. I support it as part of a larger strategy toward Iran.”

Clinton said that supporting the deal doesn’t mean that she trusts Iran or wants to normalize diplomatic relations with them, adding that she understands people’s skepticism about their motives and calling the country’s leadership a “ruthless regime that has the blood of Americans and so many others on its hands.”

“There is absolutely no reason to trust Iran,” she said.

Still, Clinton argued, supporting the Iran deal would give the United States and other countries more power to observe what Iran is doing and act quickly if they renege on any part of the deal. She outlined a five-point plan for enforcing the deal, including building a coalition of friendly nations in the Persian Gulf region to counter Iran and other groups like Hezbollah, calling out Iran for human-rights abuses at home and working to solve other conflicts in the region.

She reassured that despite Israel’s concerns about the potential agreement, the United States will be committed to ensuring their security. “You’ll never have to question whether we’ll be with you,” she said. “The United States will always be with you.”

Clinton also blasted “unserious talk” from her Republican rivals who oppose the deal. She said there’s a contrast between the “smart, serious people” who can see things differently and respect each other’s positions and the people whose motive is to “close ranks on the president … without offering an alternative.”

“Several Republican candidates boast they’ll tear up this agreement in 2017, more than a year after it’s been implemented,” she said. “That’s not leadership. That’s recklessness.”

Clinton called for a debate on the major policy differences between herself and the Republican field, calling out Scott Walker, Jeb Bush, and Marco Rubio by name.

“Where we have disagreements, we should lay them out,” she said, “like if American ground forces in Iraq should engage in direct combat, as Scott Walker wants, or if we should keep Cuba closed, as Marco Rubio and Jeb Bush want.”

She said that, above all, she hopes the debate over foreign policy can “avoid at all cost undermining America’s credibility abroad.”

“That only makes us weaker,” she said.

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