I suspect that may be as a result of the introduction of the so called "1500 hour rule" in the USA.
From August, both pilots flying US airliners must have the US ATPL equivalent, not just the captain. To upgrade to the ATPL, civilian trained pilots must have 1500 hours whereas ex-military pilots require only 750 hours.
New Qualification Requirements for U.S. Pilots - March 18, 2013
So I guess the USAF may be expecting a slight retention problem.