"Because I believe that there's a very good chance that by next election day, the national security issues in this country will be of higher priority in the eyes of the American people than the economy," he said Wednesday morning in Washington.
Santorum was the first of six Republican presidential candidates -- and one potential vice presidential nominee -- to speak at a forum hosted by the Republican Jewish Coalition.
Invoking the 70th anniversary of the attack on Pearl Harbor, the former Pennsylvania senator slammed President Obama for a policy of "appeasement" with regard to Iran that has allowed that nation to become a much bigger threat.
"I know people in this country are tired of war. But our Pearl Harbor already happened," he said.
Iran has grown stronger because of Obama's indifference, he argued. The so-called Arab spring should have begun in Iran in 2009, but Obama failed to support democratic uprisings there. And yet he threw an ally of the United States and Israel -- Egypt -- "under the bus" in the face of demonstrations that included the Muslim Brotherhood.
"The president, for every thug and hooligan, for every radical Islamist, has had nothing but appeasement," he said. "Ladies and gentlemen, learn from history."
Jon Huntsman, who spoke next, was a marked contrast in tone, focusing his remarks on the economy, and a larger sense in the nation that there is no longer trust in its leaders.
"We are in a deep funk as a people," he said. "And we are crazy in this country if we don't find the kind of leadership that we so desperately need."
Mitt Romney, Newt Gingrich, Michele Bachmann and Rick Perry are also slated to address the group Wednesday. New Jersey Gov. Chris Christie, who has endorsed Romney, will speak at a luncheon.