IMO it is much more likely that this would be a clandestine operation. They would try to infiltrate our society and introduce spies and try to keep it a secret pretty much how a CIA operation would try to topple a foreign government up to the point where they can install their own version of governance.

I would be interested whether there are alliances in our Galaxy where earth could become a member of to protect our species from direct foreign influences. It would be unlikely that all extraterrestrial societies are all either evil or benevolent.

It is difficult to make an assessment of the option as officially there are no aliens. I think the Star Trek prime directive probably isn’t that far fetched for benevolent societies however with the raising sightings that are reported (not in mainstream for sure) it appears to me that any alien presence here is held deliberately secret which IMO is not a good sign.

I think it’s likely that in our history there already has been an intervention by outer forces. The fact that humans have evolved in little more than 2 Mio years from ape to what we see now IMO cannot be only explained by evolution alone but suggests genetical modification of some sort. Whether this has been done for our benefit or not is anyones guess but it would at least suggest that the next ‘invasion’ could be in form of genetical modification of our genes.