U.S. Sen. Elizabeth Dole said that four percent is the magic number.

At the President's Day Dinner tonight, the Salisbury Republican stressed her proposal to spend at least four percent of the country's gross domestic product on defense, signaling that it would be a major issue in her ongoing re-election campaign.

That would require an additional $40 billion in fiscal year 2008.

Dole said that the military took a "procurement holiday" during the 1990s and fell behind on replacing aging equipment. She noted that while the United States is building just one Virginia-class submarine a year, China is building five a year. 

"The Air Force is flying planes that should have been retired," she said.

She noted that U.S. Defense Secretary Robert Gates and Chairman of the Joint Chiefs of Staff Michael Mullen recently testified on behalf of the resolution.