Actions against the US, UK, Israel etc are justified as part of the hybrid war these states have been fighting against one another for decades, and most of these are based on pretty flimsy evidence/accusations. Most major states could be called "sponsors of terrorism" if this is what qualifies. Of course, that's not to say that stuff like the Fatwa against Rushdie is good, or based, just that this pales in comparison to what other states have done to Iran for the past couple of centuries.