It has been debated over and over on this site if Roth was even the one to attempt the hit on Michael. I do believe it was Roth but that is just me.

Another thing I would like to mention is that, in the whole scene where Roth is yelling at Michael about Moe Green proves nothing of Roth's intent to kill Micheal. When Michael asked who ordered the hit on Pentangali, Roth went on a rant basically implying that I got over you killing Green, now you should get over the hit on Pentangali.

I don't believe that Roth was all that mad at the fact that Green was killed due to this powerful speech given by Lee Strasburg, an amazing actor and mentor.

But the main reason wasn't even a threat to Roth's casinos. Roth just didn't like to be equally powerful He wanted to be alone at the top. So Roth led Michael in and atempted to kill him.