The same thing that it’s been for almost every war the US has been involved in since WWII: We want a government that will be good for US business and military interests. Iran in particular we’ve been fucking around with for over half a century. If the question is why now? It’s anyone’s guess. It’s Trump, he isn’t exactly the most sane president we’ve had, even amongst the evil bastards. Distraction from Epstein? Distraction from shitty domestic policy? Trying to create enough chaos to try to justify canceling elections? Israel pushing for it particularly hard? Trump just randomly losing it over something stupid? A spot opened up in our war calendar? Who knows?