I am not trying to untire! this thread but I only picked this up now.... and am confused! why the Rosato brothers tried to kill Pentangeli?

Pentangeli's house - Michael to Pentangeli:
Quote
Extracts:
Settle these troubles with the Rosato brothers

He [Vito] taught me -- keep your friends close but your enemies closer

Now if Hyman Roth sees that I interceded in this thing and the Rosato brothers failed him he's gonna think his relationship with me is still good Capide?

What was Michael expecting to happen at the Pentangeli-Rosatos meeting? I believed, in the old days! -
  • Michael was not expecting Pentangeli to come to any harm other than the humiliating back down, perhaps handing over the three territories and in the process looking weak etc.
  • Besides if Pentangeli is killed and Rosato brothers, Roth's ally take over the Corleone operation then Michael loses his muscle and becomes just another casino operator, easy pickings for anyone
  • Hence Michael would never want to lose his muscle which is the only thing that makes Michael untouchable!
  • and Michael can't afford to let his man's murder go unavenged - danger of starting another war

So....
  • Why would Michael envisage the Rosato brothers would fail Roth
  • and How