MCU: 14 Things You Learn Rewatching The Avengers
2. The HYDRA Theory Makes A Lot Of Sense
There is a theory out there that suggests that HYDRA brought together the Avengers in order to destroy them, using Arnim Zola's superpower algorithm to identify key targets and their infiltration of S.H.I.E.LD. to greenlight the Avengers Initiative. It's suggested as the only explanation for them allowing the superhero team to exist.
The Avengers feeds into that idea as well: given that Powers Boothe's Gideon Malick sits at the head of the World Security Council and it's him who sends the nuke to New York, it would seem that this was HYDRA's plan all along.
They wanted to bring the Avengers together for this sort of opportunity and Malick took his chance to try and sneak HYDRA's agenda to destroy them through. Sadly for him, he was thwarted by an uncharacteristic heroic sacrifice by Tony Stark.