DEARBORN, Michigan, 11 October 2007 — Newcomer Fred Thompson muscled into his debut debate with Republican White House rivals Tuesday, avoiding gaffes, vowing to battle “Islamic fascism” and declaring the race “boring” without him.

Despite a nervy start and mocking reviews since he entered the fray last month, the screen star and former senator grew in confidence in his first televised clash with party foes.

Thompson dodged snares laid by debate moderators and top rivals, New York’s ex-Mayor Rudolph Giuliani and former Massachusetts governor Mitt Romney, called for a robust foreign policy and backed the Iraq troop surge policy.

“It is a global war - Islamic fascism has declared it upon us,” said Thompson, who played a gritty prosecutor in internationally syndicated crime drama “Law & Order.”

“They play by no rules and they are intent on bringing down Western civilization and the United States of America,” said Thompson, hoping to follow Republican idol Ronald Reagan from the silver screen to the Oval Office.

Romney, who runs well in early voting states, and Giuliani, the national front-runner, carried on their increasingly intense private battle in the debate broadcast by business channel CNBC.

Romney also took a swipe at Thompson, who is targeting dismay at the presidential field among social and religious conservatives. “This is a lot like ‘Law & Order’: it has a huge cast, the series seems to go on forever ... and Fred Thompson shows up at the end.” Thompson hit back, “I’ve enjoyed watching these fellows, (but) I’ve got to admit, it was getting a little boring without me.”

The actor, who has faced criticism that he is not up to speed on current events, also dodged a sucker punch question, confidently answering “Harper” when asked to name the Canadian prime minister, Stephen Harper.

Romney branded Iranian President Mahmoud Ahmadinejad a “rogue and a buffoon” and criticized his trip to the United Nations General Assembly last month. But his rivals will pounce on his response when asked whether a US president should request authorization from Congress before launching a military strike at any future Iran nuclear weapons plant. “You sit down with your attorneys and tell you want you have to do,” he said, before adding the president always had to act in the best interest of the United States.

Former Arkansas Gov. Mike Huckabee said he would attack Iran in a “heartbeat” if it was an immediate threat, but long-shot candidate Ron Paul said the notion that Iran endangered the US mainland was “preposterous.” Senator John McCain pledged to consult Congress before mounting a hypothetical strike on Iran, which he said “is, maybe, closer to reality than we are discussing tonight.”

Iran has denied accusations that it intends to develop nuclear weapons.

Thompson sparked intense anticipation by hovering for weeks on the edge of the Republican field, and is trying to exploit dissatisfaction among conservatives with their 2008 choices.