How It Would Work Having realised that he's the idiot who went off-plan to create Ultron and unwittingly almost killed everyone in order to save them all from dying, Stark could realise that he's actually the problem, and needs regulation and accountability. The Evidence Tony's arc so far has taken him from megalomaniac weapons dealer through self-confessed playboy superhero, self-sacrificing genuine hero, to PTSD sufferer and finally over-zealous nuclear deterrent guy in the space of the two phases. We've already seen flirtations with the idea of his guilt (Ultron wouldn't have been created without it), and despite his bravado, he should now be further down the same path of self-doubt and conscience wrestling than he was before he even made the fatal decision to invent Ultron. And the only logical response would be to bring in regulation, rather than a weaponised deterrent. The Likelihood Again, it's bound to be part of the issue, but not the trigger. It's hard to imagine that Stark's guilt alone would be enough for him to go to the government to set up the Accords: it would have to be part of the response to the elusive trigger event that drives him there.