Excellent article about whether the military is our own Fifth Column

New York Post Online Edition: postopinion For those of you wondering, here is a nice summary about its origin:

People willing to cooperate with an aggressor against their own country. The term originated in a remark by Francisco Franco, the Spanish dictator, that he was marching on Madrid with four columns of troops, and that there was a “fifth column” of sympathizers within the city ready to help.