The word "撤军" is formed by combining the character "撤", meaning to withdraw, which is constructed from the hand radical "扌" indicating manual action and the component "徹" serving as a phonetic and semantic element, with the character "军", meaning army, composed of the cover radical "冖" over "车" symbolizing military vehicles. Together, they create a verb-object compound where "撤" denotes the action and "军" the object, directly conveying the meaning of withdrawing military forces.