Wherever they are put.
Base in Germany? Crash course in German. Carrier off Ethiopa? Crash course in Ethiopian. Guard duty in Cuba? Crash course in Cuban Spanish. Duty in the Philippines? Crash course in Filipino.
Peacekeeping in Iraq? Crash course in Iraqi Arabic.
Teaching language always teaches some culture. Both would help stop the insularity of US troops. It's ironic that most foriegners appreciate when tourists try to learn some local language and customs *because* of US tourists who fail to do both. Imagine the response if US troops were to do this.
Wade.