(According to this source http://www.ssa.gov/OACT/TRSUM/index.html the projected deficit was going to be $41 billion as of the beginning of August, a couple of months before the end of FY 2010).

According to Wikiepedia FY 2010's DoD budget, all categories except the black budget was $663.8 billion; that's a bit less than the year's Social Security expenditures. As for it's relationship to the whole budget (http://en.wikipedia.org/wiki/US_defense_budget#Military_budg...):

"The U.S. Department of Defense budget accounted in fiscal year 2010 for about 19% of the United States federal budgeted expenditures and 28% of estimated tax revenues. Including non-DOD expenditures, defense spending was approximately 25–29% of budgeted expenditures and 38–44% of estimated tax revenues."

The "including non-DOD" apparently includes:

"This does not include many military-related items that are outside of the Defense Department budget, such as nuclear weapons research, maintenance, cleanup, and production, which is in the Department of Energy budget, Veterans Affairs, the Treasury Department's payments in pensions to military retirees and widows and their families, interest on debt incurred in past wars, or State Department financing of foreign arms sales and militarily-related development assistance. Neither does it include defense spending that is not military in nature, such as the Department of Homeland Security, counter-terrorism spending by the FBI, and intelligence-gathering spending by NASA."

A substantial fraction of which can't be reasonably scored as "military spending".