Republican presidential candidate Rudy Giuliani, who has put his leadership as mayor of New York during the September 11 attacks at the center of his campaign, said Tuesday evening that "Islamic terrorism" didn't begin that fateful day in 2001 but decades earlier with attacks on Israelis. Telling the audience at a Maryland synagogue that Israelis and Americans are now bound in the same war against Islamic militants, Giuliani stressed the need to be "on offense against terrorism" to warm applause. Specifically, he warned that a retreat from Iraq could plunge the region into wider sectarian conflict and create a failed state run by the same sorts of Islamic militants that now run Gaza in the form of Hamas. "What happened in Gaza is a microcosm of what's going to happen in Baghdad" if the United States withdraws, he said. "It will become something that inflames the entire region." He also took a hard line against Iran, telling the leaders of the Islamic Republic: "You are not going to be allowed to become a nuclear power. No how, no way, just not going to happen." Given the situation in Gaza, Giuliani backed Prime Minister Ehud Olmert's approach to bolstering Fatah, but cautioned against raising expectations and making the same "mistake" the Clinton administration made with its reliance on Palestinian leader Yasser Arafat during the Oslo process. Giuliani, who is leading in many surveys on the Republican candidates, also ripped Clinton's handling of terror attacks on Americans in the 1990s, calling his response "inadequate." "I'm not blaming anybody back then," he said. "What I am saying is, I do blame people after September 11. Now you have to get it. Now you have to understand that the terrorists are in a war against us. George Bush is not making it up." "Rudy's arrogance has gotten the best of him," the Democratic National Committee said in a one-paragraph response. "How can a man who failed to prepare New York City for a second attack after the first one, who sent firefighters and emergency workers into Ground Zero without respirators and quit the Iraq Study Group to raise money, keep America safe?" Giuliani spent much of his time before the crowd, which had come to listen to the latest in a serious of candidate forums sponsored by the Jewish Community Relations Council of Greater Washington, pointing to his successes as mayor of New York. He also emphasized his ties to Israel, noting that as mayor three of his four trips abroad had been to Israel. On one occasion he came at Olmert's invitation to join him in riding a Jerusalem city bus following a suicide bombing. And Giuliani proudly recalled kicking Arafat out of a UN concert while mayor, for which he received loud applause. "I'll tell you the real reason I threw out Arafat: He didn't have a ticket," he said to audience laughter. "I believe in the broken windows theory," Giuliani said, referring to his much-touted approach as mayor to reducing urban crime by first prosecuting small offenses such as vandalism. "So you start with, 'you got to pay for your ticket.'" The Associated Press contributed to this report.