That's the goal of a smaller military under Secretary of Defense, Chuck Hagel. Inevitable discussions turn to downsizing after a war (on in this case two). Military forces have to grow to meet the increased OPSTEMPO but once they forces are withdrawn, there is little reason to maintain large numbers of troops and equipment.
According to USATODAY, the Secretary said "To that end, the Pentagon is liquidating much of its $40 billion fleet of Mine Resistant Ambush Protected vehicles, the signature truck of the wars in Iraq and Afghanistan. They're heavy and lumbering and associated with wars of occupation. Definitely passé." Interesting, a similar mindset in the late 1950s said missiles meant that fighter jets would no longer need to be armed with canons. Then in the Vietnam war it was determined that the F-4s were are a tremendous disadvantage because they lacked canons. Or the mindset that said large maneuvering units fighting in the desert were a thing of the past…until Desert Storm. Or what about the mindset that wanted to ignore the guerrilla type warfare of Vietnam…only to see it again in Afghanistan.
Let's be honest. The Department of Defense is looking to cut its budget and is using these arguments to support that end. If you want a truly expeditionary, quick reaction force you already have it in the US Marine Corps. The doctrine of the USMC (MCDP 1-1, dated 1997) it states, "The United States Marine Corps is a key instrument in the execution of American national strategy. Marine expeditionary forces possess extraordinary strategic reach. As an expeditionary force-in-readines, the Marine Corps has been consistently called upon to implement key elements of our national security strategy and its supporting national military strategy."--FAS.ORG
The Marine Corps is designed to be light and lethal. For long term engagements, the Army follows with heavy forces. Making the Army lighter doesn't make much sense as that's not what they do or how units are doctrinally created.
The Army is already on a path to shrink from 540,000 soldiers to about 490,000 by the end of 2015, and will likely slide further to 420,000 by 2019, according to reports. (Defense News)
Why then do we need to look elsewhere for a nimble, small force able to rapidly respond? According to Paul McLeary in Defense News, "Instead, look for an Army with fewer soldiers and more robots".
Robots don't require pay, medical benefits or pensions. They also very good for OPSEC as they don't tell their friends or sweethearts were they are going or what they've done. Robots don't need promotions or incentive pay. Robots don't talk to the press.
Future wars (and the future is very soon) will see more robots (both air as well as ground) waging combat as well as performing logistics functions. The move towards more robots brings up a very ugly eventuality that without risking American lives Washington will become more willing to send drones into harm's way. If there is no risk to us, what incentive do future Presidents and members of Congress have to not send in a force of robot soldiers to quell hostilities in some country? How will we even know?
Update: Gen McChrystal was quoted in RT.com talking about drones, "“There's a danger that something feels easy to do and without the risk to yourself, almost antiseptic to the person shooting, doesn't feel that way at the point of impact. And so it lowers the threshold for taking operations because it feels easy, there's a danger in that"