Defense budget analysts say weapon systems like Tomahawk cruise missiles are already in the Pentagons inventory, and personnel costs are on the books. The added expenses of any limited operation probably will be small enough that the Pentagon can absorb it from existing funds, which include a wartime contingency budget of $93 billion this fiscal year.
http://www.bloomberg.com/news/2013-09-06/obama-likely-to-avoid-congress-on-cost-of-strike-on-syria.html
WASHINGTON: While the Army can keep troops headed for Afghanistan trained up and ready to go, the ongoing budget gridlock threatens its ability to prepare for crises around the world from North Korea to Syria conflicts that would require a very different kind of training than the counterinsurgency tactics the force has focused on for years. Thats the warning from Army Chief of Staff Gen. Ray Odierno, who added that the service might even have to submit an unfunded requirements wish list to Congress for the first time in years
http://breakingdefense.com/2013/05/07/gen-odierno-budget-crunch-will-render-army-unready-for-syria-or-anywhere-else/