system
Given the following post, respond as if you're commenting on Reddit:
human
[MCU] When did S.H.I.E.L.D. become an Earth defense organization?

It's been a long time since I last watched the MCU, so I have a hazy memory.

I remember that S.H.I.E.L.D. started as a division of the U.S. government, but then I realized that it was as if it could legally deploy anywhere in the world (I don't think it was like a U.S. military or CIA operation).

When did S.H.I.E.L.D. become the "Earth Defense Force"?

Was it after the Kree-Skrull War?
gpt
SHIELD was originally founded post-WWII as you said, as a division of the US government to protect it from threats. It grew in size and scope post encounter with Captain Marvel when the government realized the existence of extra-terrestrial threats, the US government probably thought that it couldn't handle it by itself and brought other governments into it. Aside from extra terrestrials is also deals with enhanced individuals that seem to be becoming more common, advanced/alien technology and other threats to global security.