This cartoon by Clay Bennett from the Chattanooga Times Free Press is a comment on President Obama's dismissal of U.S. General Stanley McChrystal from the top command post in Afghanistan, following the General's disparaging remarks about the White House leadership in an article in Rolling Stone magazine.
In the cartoon the General has shot himself in the foot. In fact, this is a visual pun since, used in the figurative sense, to shoot oneself in the foot is an idiom. If you shoot yourself in the foot, you do something which damages your ambition, career, etc. • Slovenia then almost shot themselves in the foot at the beginning of the second half.