Government is legit exactly because the masses give it legitimacy. (Replying to your title)
"YOU do not have the right to initiate violence" Of course you do, this is a sovereign right of every individual and government. The right to declare war. The law of the jungle. "Preemptive strikes" sound familiar?
USA is not playing by the book and uses false flags and media brainwashing to justify its aggression but the fittest survive, right? Its Darwinian brainwashing combined with a zero-sum game mentality that has motivated the USA to make a move for the resources and strategic locations of the world (combined with its ridiculously enormous debt). It wants to create a one world system of government, a global hegemony with USA on top. USA has declared war but not on one country in particular, but with the whole world. You're either for or against America - that's the reason for regime change in so many countries. What happens when American citizens turn against America?