Audiences worldwide love action movies. When films feature uniformed personnel, planes, or ships—or, better yet, are military-themed, Hollywood routinely travels to the Pentagon. The Air Force, Army, Marine Corps, and Navy all share offices geared towards Hollywood in the same Los Angeles office building. Over in Washington, the Defense Department quietly maintains a Film Liaison Unit that closely collaborates with filmmakers. It’s one of the marketing world’s most interesting (or, depending on your views, unsettling) cross-promotional relationships. And odds are you wouldn’t be watching Battleship without it.