boots on the ground

Meanings

1. The ground forces actually fighting in a war or conflict, rather than troops not engaged or other military action such as air strikes.
2. The military policy of using ground forces.
3. Personnel operating in an area of interest.
4. The state or condition of being physically present at a place of interest in order to ascertain the current situation.
5. Used other than figuratively or idiomatically: see boots, on, ground.

Etymology

First appears c. 1980 in the US. Attributed to the United States General Volney F. Warner, as quoted in the Christian Science Monitor (April 11, 1980) in reference to the Iranian hostage crisis