Armchair warrior is a pejorative term that alludes to verbally fighting from the comfort of one's living room.
Typical "armchair warrior" activities include advocating sending troops to settle a conflict, lobbying to keep defense jobs to make outdated military equipment as part of the military-industrial complex, or to make political messages on radio or television talk shows in favor of using armed forces in a conflict over trying diplomatic channels.
An early example of the term "armchair warrior" appeared in the 1963 Twilight Zone episode No Time Like the Past, in which a time traveler to the late 1800s uses the term in a speech directed towards a banker who is calling for sending young soldiers to fight a war against American Indians.
[1][2] The show's director, Rod Serling, had received a Purple Heart for injuries incurred while serving as a paratrooper in World War II.
It is more of a variation of "chickenhawk", which was originally a slang term used during the Vietnam War to describe a superior officer that was not on the frontlines.