Agents of STRIKE
The Nova Corps
The Nova Corps are a galactic peacekeeping force, essentially an interstellar equivalent to SHIELD.
Based on Xandar, they attempted to enforce the Xandar Treaty (until the Second Kree-Skrull War began) and other interstellar treaties, and protect the helpless and other general do-gooding. They also pursue extra-terrestrial criminals beyond normal jurisdictions, which means sometimes they might find themselves on Earth chasing some alien fugitive.
Some Nova Corpsmen are reasonable and easy to get along with. Some are absolutist and intolerant towards local laws and customs, including our own. Be very careful when interacting with them, if you must at all.