U.S. Defense Secretary Leon Panetta quantified a super committee failure in real numbers on Monday: ground forces shrunk to 1940-levels; a naval fleet rivaling 1915's; and the smallest Air Force in history.

The figures come from a letter Panetta wrote to two senators on the Armed Services Committee, U.S. Sens. John McCain, R-Ariz., and Lindsey Graham, R-S.C.

The Pentagon already faces a $450 billion cut as a result of President Barack Obama's call to shrink defense spending. Should the super committee, also known as the Joint Select Committee on Deficit Reduction, cuts in defense spending could reach $1 trillion, Panetta said.

Defense Cuts Could Prevent Future Projects

The cuts could stymy future building projects and lead to furloughs for civilian employees in 2013, according to the letter.

Such a large cut, applied in this indiscriminate manner, would render most of our ship and construction projects unexecutable - you cannot buy three quarters of a ship or a building and seriously damage other modernization efforts, Panetta wrote.

The letter reads as a laundry list of multiple outcomes to defense cuts, and Panetta's overall suggestion is to maintain current discretionary spending levels.

The super committee has just over a week until it must present a plan to cut at least $1.2 trillion from the federal budget deficit. Should it fail, an automatic trigger cut would be implemented over the next decade.