In his work "On War," Carl von Clausewitz noted that "war is merely the continuation of politics by other means." While most military leaders would prefer their civilian counterparts do the work of foreign policy, there are elements of military policy in American foreign policy.
The Defense Security Cooperation Agency handles arms sales between American firms and foreign governments.
The Defense Manpower Data Center provides information on where military personnel are stationed, both by US state and country (with some countries not reported due to security issues.)