Character Analysis
"[Nick Fury's] secrets have secrets," Tony Stark claims…and it's hard to argue with him.
This is a universe full of gods and aliens who can level cities in the blink of an eye. Nick Fury's the guy keeping an eye on all of them and constantly thinking up solutions to impossible problems. That makes him sneakier than anyone else in the film… and considering this film contains the Norse god of sneakiness, that's saying something.
Fury's also an "ends justify the means" kind of guy. He's got the safety of the Earth in mind, and if he has to manipulate a few people to maintain it, that's just what he'll do.
If you want an example of this, just check out the Tesseract. Nick's desire to keep everyone safe leads him to cross a few lines—you know, in the form of working with an insane dimension-bending wormhole. The heroes he's gathered give him a piece of their minds once they figure out his reindeer games:
THOR: Your work with the Tesseract is what drew Loki to it... and his allies. It is a signal to the Realm that Earth is ready for a higher form of war!
NICK FURY: Higher form? You forced our hand! We had to come up with some way that we could...
But Fury does what he does because he believes it will save lives. And that's the same impulse that leads him to push the heroes to finally become the Avengers.
NICK FURY: There was an idea, Stark knows this, called the Avengers Initiative. The idea was to bring together a group of remarkable people to see if they could become something more. To see if they could work together when we needed them to, to fight the battles that we never could. Phil Coulson died, still believing in that idea. In heroes.
That doesn't necessarily make him trustworthy, but it does make him the guy you can trust to be acting in everyone's best interests. In other words, he's the perfect recruiting tool for this particular band of superheroic misfits.