Remember Barack Obama's slip where he promoted a "Civilian National Security Force"? Say hello to the Defense Department's new "Civilian Expeditionary Workforce" plan. From defenselink.mil/news/newsarticle.aspx?id=52840:

The Defense Department is forming a civilian expeditionary workforce that will be trained and equipped to deploy overseas in support of military missions worldwide, according to department officials...

[Defense Department Directive 1404.10] emphasizes, however, that volunteers be sought first for any expeditionary requirements, before requiring anyone to serve involuntarily or on short notice. Overseas duty tours shall not exceed two years.

Employees in deployable-designated positions will be trained, equipped and prepared to serve overseas in support of humanitarian, reconstruction and, if absolutely necessary, combat-support missions.

Note that the serving "involuntarily" does not refer to all civilians, only to civilian employees of DOD. See this for more.