Vice President Joe Biden delivered a forceful defense of the Obama administration’s nuclear agreement with Iran on Thursday, telling some of Atlanta’s most influential Jewish leaders that the deal would help bring about a more secure Israel.

Biden told the hundreds crowded into the Ahavath Achim synagogue in Buckhead that the pact would help prevent Iran from getting a nuclear weapon, positioning himself in the process as the candidate who would continue President Barack Obama’s legacy were Biden to run for president.

“I could take a whole evening to speak to this, but this is a good deal,” he said during an evening address on foreign policy. “And if we walk away from the deal, as some of our critics propose, we’d gain none of the benefits.”

Sanctions would soon collapse if the deal unravels, he said, and Iran would be a “few short months away” from getting the material needed to build a nuclear weapon.

During a question-and-answer session, Biden danced around the question that’s dogged him for months, as speculation grows about whether he will challenge Democratic front-runner Hillary Clinton for the party’s nomination.

An audience member wanted to know: Will he run?

“The honest to God answer is I just don’t know,” Biden said.

Georgia’s Democratic establishment is firmly behind Clinton, but many rank-and-file Democrats are urging Biden to jump into the race because they fear the scandal-scarred former First Lady can’t win in November 2016.

Biden used the speech to highlight his foreign policy chops, outlining what would be his doctrine for military intervention. Such an attack, he said, would have to protect vital American interests and lead to sustainable results.

He rejected the calls from some Republican presidential candidates to deploy American ground forces to thwart the Islamic State’s spread through Iraq and Syria, saying that locals must “stand up” for themselves to bring a lasting peace.

And he called for massive new investments in U.S. infrastructure and workforce training.

“If we do those two things, I guarantee you, we will be the most dominant force in the 21st century,” he said.

The Obama administration’s nuclear deal is a divisive subject within the Jewish community. Many Jewish and Israeli leaders oppose the deal.

Majorities in Congress are likely to oppose the deal when it comes up for a vote. President Obama would then veto the disapproval. And he has lined up enough supporters in the Senate to block an override of the veto.

Biden sought to soothe concerns over the administration’s policy on Israel, calling the administration’s support for the Jewish nation “absolutely unshakable.”

“This president has done more to advance Israeli security than anyone in American history,” he said.