 Perhaps forewarned or anticipating the attack, the VC had chosen to evade allied forces by either fleeing across the border into Cambodia or hiding in complex underground systems.As a result, one of the largest military ground operations since the Korean War and the single largest ground operation of the War in Vietnam was characterized by skirmishes and other small unit actions rather than large-scale combat.Allied troops were overwhelmingly engaged in extensive searches and patrolling during daytime and ambushing during the night; casualties were suffered primarily from sniper fire, land mines, and booby traps.