system
Given the following post, respond as if you're commenting on Reddit:
human
[Marvel] Why did the US Army not ask Captain America to resume service?

I would think that Cap would be pretty useful, and I’m sure that he would do it in a heartbeat.
gpt
SHIELD got him first. By the time the Army would be in a position to make the offer, it's post-Chituari Invasion, and Cap just watched the government try to nuke NYC. He's probably not too keen on being part of a rigid chain of command at that point, and values being able to set his own agenda to some degree.