The US military directly sponsors or promotes Hollywood movies with the benefit of gaining fairly good control of the overall messaging surrounding the military in the film.

Zero Dark Thirty is perhaps the most egregious example of this, with the CIA consulting and the film depicting that the information leading to Osama Bin Laden's location was extracted under torture from an inmate (it was not).

Many American films are not even casually not propaganda. The way you think about the US military is shaped and influenced by the influence the US military gets from fronting money, consulting and equipment appearances to appear in Hollywood films (with sometimes some weird consequences - for example they refused to back The Avengers because they felt SHIELD undermined the portrayal of the US, but were happy to back The Winter Soldier because in that SHIELD isn't the US DoD and goes down).[1]

[1] https://gamerant.com/marvel-military-propaganda-explained/