* During World War II, the US experimented with radio-guided bombs, with mixed results, with such early "smart munitions" seeing relatively little use. In the immediate postwar period, the primary focus was on the nuclear option, and as a result, there was no great interest in smart weapons. It wasn't until the 1960s that interest revived in a big way, with smart munitions playing a significant role in combat near the end of the Vietnam War. They have since become the primary ground-attack weapons in the US arsenal. This document provides a history and description of US guided bombs.