G.I. Joe: Retaliation explodes into theaters June 29, and we have a first look at the new trailer for the highly anticipated sequel starring Dwayne Johnson, Channing Tatum and Bruce Willis! Video: ET Exclusive: 'G.I. Joe 2' Set Visit Is the President of the United States real, or an impostor? G.I. Joe: Retaliation finds the Joes not only fighting their mortal enemy Cobra, but forced to contend with threats from within the government that jeopardize their very existence.