“To whom did S.H.I.E.L.D. answer? Did we work for S.H.I.E.L.D.?"

Moviegoers and comic fans know that S.H.I.E.L.D., led by Samuel L. Jackson’s super-spy Nick Fury, is an international peacekeeping/global surveillance/crisis response/quasi-military organization. But its relationship with the United States is murky. And that basically stopped the U.S. military, which is normally eager to cooperate with the film industry on blockbuster movies, from teaming up with the Avengers.

“We couldn’t reconcile the unreality of this international organization and our place in it,” Phil Strub, the Defense Department’s Hollywood liaison, tells Danger Room. “To whom did S.H.I.E.L.D. answer? Did we work for S.H.I.E.L.D.? We hit that roadblock and decided we couldn’t do anything” with the film…

But the ambiguity around what exactly S.H.I.E.L.D. is provides a vexing complication. If it’s an American governmental agency, what kind of constitutional authority does it exercise over the military? If it’s an international body, as the movie text suggests and Strub determined, are U.S. military personnel and equipment on loan to it through some kind of United Nations Security Council resolution? The questions may seem picayune, but they’re precisely the stuff that can cause an image-conscious military to yank its cooperation from a movie.