During the Vietnam war the Viet Cong or "VC" for short were the insurgents. VC were originally a loose outfit of guerrilla warfare fighters using strictly unconventional methods of war and rarely ever fought in the open with conventional methods. This made the war a number of times harder for US troops in Vietnam. Instead of fighting out in the open as the US was used to or fighting an urban conflict, the US was now forced to drive deep into the jungle and draw out VC one at a time. This was a long and frustrating task as America had never fought a jungle war before, and was not used to this method of warfare. The VC's ability to hide and use their knowledge of the geography to their advantage led to psychological affect on American troops that the enemy was virtually everywhere including right under their noses. The VC dug vast tunnel systems and operated underground making it increasingly harder to find them. This also made it much more dangerous for American troops as they could be attacked at any time unknowingly.