Romney, who chose not to seek re-election last month, won't formally declare his presidential candidacy until January, say senior advisers. In the meantime, he's taking a crash course to deal with what could be one of the most significant shortcomings: his lack of national security experience.

While Bush and his predecessor, Bill Clinton, were governors who also lacked national-security bona fides, they governed in the pre-Sept. 11 era, when a presidential candidate had to be more concerned about correctly stating the price of a quart of milk than outlining positions on Iraq, Iran and North Korea.

Romney's cram course has involved overseas trips and policy pow-wows. He's currently on an Asian swing and is meeting with policymakers in Japan, China and South Korea. He was out of the country when the Iraq Study Group released its recommendations to Bush and Congress and, unlike McCain, didn't make public statements about the report.

Republicans such as Romney "don't want to take on the president, but they don't want to take on public opinion either," said John Pitney, who teaches courses on Congress and the presidency at Claremont McKenna College in Claremont, California. "So they take off."

Romney has also met with retired generals, former U.S. secretaries of state and think-tank experts in pursuit of a revised U.S. strategy for Iraq. While he has visited the war-torn country, he lacks McCain's expertise when it comes to suggesting a path out of the quagmire.

Romney will outline a series of positions on international affairs next year, said Tom Rath, a New Hampshire Republican committeeman who has joined his team as an adviser. "You'll see a very clear statement of America's role in the world and how that role in the world would be amended," Rath said.

On the domestic front, Romney is looking for areas where he can sharpen differences with McCain. One target: Senate-backed immigration legislation, championed by McCain, which would give undocumented workers a path to U.S. citizenship. Aligning himself with House members, Romney stresses tough border enforcement over a new guest-worker plan.

Creating a Contrast

Romney also might create a contrast with McCain, whose primary interest in the tax code thus far has been to criticize loopholes, by signaling an interest in broader overhaul of the tax code. He has signed up former Bush administration economists Glenn Hubbard and Greg Mankiw, advocates of tax simplification and incentives to spur capital formation.

While McCain attracts criticism from some Republicans for his fights with the White House on issues ranging from prisoner interrogation methods to campaign-finance reform, Romney may draw fire for altering his stance on several social issues as he shifted from being a governor of one of the most Democratic states in the union to a presidential candidate.

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