The US military loves the movies. There’s nothing better for them than a good action movie that makes military service look awesome, and so various branches of our armed forces often cooperate with producers and studios to put military gear into films.

But the collaboration can come to a quick end if the notoriously sensitive military senses that portrayal of the armed forces will be out of its control. And so the Pentagon put the kibosh on a collaboration with Marvel Studios for The Avengers. The reason? The murky relationship between super-spy agency SHIELD and the rest of the US government, and specifically the military.

Wired quotes Phil Strub, the Defense Department’s Hollywood liaison, saying,

We couldn’t reconcile the unreality of this international organization and our place in it. 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].

The site notes that it wasn’t quite that the defense department wouldn’t do anything — the National Guard has a presence in the film, and digital stealth fighters (F-22 Raptors and F-35 Joint Strike Fighters) are digitally added to the SHIELD Helicarrier, though those planes didn’t require participation from the US government.

The reason this is funny is that the US Navy has worked enthusiastically with ‘unrealistic’ films in the past. Various branches of the military collaborated with the production of Iron Man, and on Michael Bay films. The Navy recently collaborated with Peter Berg on his Michael Bay copycat movie Battleship. If you think The Avengers is unrealistic, just wait until you see the third act of Battleship. Swipe for the spoiler text if you so desire: In a last-ditch stand against the invading aliens, Taylor Kitsch leads a group of aged Navy veterans as they refit a mothballed ship to go into battle. (Spoiler ends.)

But Wired points out that there’s a specifically interesting point here: that SHIELD’s precise place in the US bureaucratic map has always been murky, and this could end up being an opportunity to define the agency’s role in more specific terms. For a continuity-conscious set of films like Marvel’s, that could be a nice extra detail.