Stop taking away responsibility for US actions. As you say Israel has asked US for a war with Iran everyday for 20 years and US has said no everytime. Now they said yes. So clearly US was able to say no and the choice to say yes was theirs.

Of course the US are entirely responsible for their actions. They're doubly responsible because not only they engaged in a reckless and illegal war, but also because they did it out of subservience to another country. The US politicians who promptly pledge their loyalty to Israel every time they're asked to (i.e. almost all of them), they are fully responsible.