O'Hanlon and other analysts are characterizing Romney's call to spend 4% of GDP on defense as an aspiration rather than a campaign pledge. For 2013, the defense budget would return to the fiscal 2011 spending level, before Congress passed the Budget Control Act mandating a reduction in all government spending—including defense. The increase in spending would be phased in over time, explains Mackenzie Eaglen, a fellow at the American Enterprise Institute and adviser to the Romney campaign.

“This goal is predicated on a larger federal spending plan that would look very different from today's,” Eaglen writes. “Further, as tax policies are reformed, federal spending on entitlements are reformed to last longer than current budget plans would allow, and the regulatory burden is reduced on the private sector, then presumably the economy would see more growth and a 4% defense budget goal becomes more affordable.”

Eventually, additional money would allow the Pentagon to maintain 100,000 more soldiers and Marines than Obama's plan calls for. Romney would seek to build 15 ships per year, rather than the nine contained in Obama's request. He also told a Virginia television station he would order production of Lockheed Martin's F-22 Raptor to restart, though even an air power advocate suggests that might have been a misstatement—Romney might have meant buying more F-35 Joint Strike Fighters, instead.

“Romney has said he will focus on rebuilding U.S. military strength, if elected.” Eaglen says. “He believes that U.S. leadership requires a resurrection of President Ronald Reagan's vision of 'peace through strength,' where investing in hard power capabilities helps to secure national policy objectives without fighting.” Romney would value “power-projection capabilities,” make up for underfunded maintenance and modernization and fix the acquisition system, Eaglen says.

With economic growth and increased defense spending, Romney also foresees a return to larger investments in Boeing's Ground-based Midcourse Defense (GMD) System. The president canceled sites planned for installation in Poland and the Czech Republic.

“Mitt would reserve the option of reverting to [former] President [George W.] Bush's original plan of deploying proven interceptor technology in Poland if it becomes clear that Iran is making faster progress on developing long-range missiles than the Obama plan assumes or if the new technologies on which the plan relies fail to materialize in a timely fashion,” says the Romney campaign web site. “If Iran is going to deploy intercontinental missiles sooner than 2020, the United States should retain the option of defending against them.”

The economic and political pictures of 2012, however, are very different than those from 2009, which has posed problems for Obama in realizing his proposed 2013 budget.

In February, the Pentagon requested two politically unpalatable choices—a new round of base closures, and reductions to the Air National Guard's fleet.

Opposition to Obama's proposal for two years of base closures has its roots in the 2005 round, which cost money on the front end and produced vague savings on the back end. But it was also a difficult sell to lawmakers on the idea of potentially losing a major presence in their districts in an election year.