This is what Michael tells Tom before he heads off to Miami.
He never tells Rocco or Neri, but it appears they fell into line and took Orders from Tom (i.e. Neri's "help" in setting up Geary). Michael seems to know instantly that it was Roth who tried to kill him, because he goes directly to Roth after the attempt, to "keep his enemies closer." But did he tell Tom he suspected Roth? Not in the script he didn't, and that's a huge mistake because if Tom had known it was Roth maybe he would have paid closer attention to the "death" of Pentangeli, through his sources in the NYPD. This would have allowed Don Tom to do something either to get word to Pentangeli to keep his mouth shut, or to start to prepare for the inevitable hearings that Pentangeli's confession would cause. Once again, Michael's secretiveness is a big part of his undoing. Moreover why did he have to go to the trouble of telling Tom he was going to be "the Don." He never really was anything more than an acting Don while Michael went to Miami, New York and Havana.

Oh... DonT... this was just a tactic by Mike to people skill Tom and make him feel the acceptance that he knew Tom always desired from him (hence his speech about being close to Sonny and not Mike growing up and being considered a brother). Mike played to this to make things go as smooth as possible. I always get the feeling that Michael never really respects Tom as much as Sonny or definately Vito does.

Michael is a manipulator, plain and simple. Manipulators have differing levels of skill. Michael's appears to have been among the best. He tells Tom what he thinks Tom needs to hear so that Tom will do his bidding. He reads people pretty well also. He reads Tom as wanting his approval which Tom believes he gets by his taking Tom into his confidence.

couldn't have said it any better myself oliv ;-)

Michael the Manipulator played Tom like a violin. The fact is, he needed Tom (for once) because (for once) he told the truth: "Right now, you're the only one I can completely trust." The reason he didn't tell Tom that he already knew Roth was behind the attack was that he'd kept Tom out of all the previous Roth negotiations--and even at that dire point, he wasn't going to let him in. If Tom had known that Michael blamed Roth, why, he'd actually be capable of making some decisions on his own--like (as dt said) looking closer into Pentangeli's alleged "death." Heaven forbit, he might even have been more useful to Michael--a real consigliere.

Do you view this as Tom's fault, or Michael's? I view it as Michael's, as he kept Tom in the dark on too many things for him to be a "real consigliere." His hands were bound.

The fault was mainly Michael's. An obsessive controller, he had to do everything by and for himself--and that included his taking over the role of his own consigliere.

To be fair: Michael wasn't wrong when he told Tom (in GF) that "you're not a wartime consigliere." He wasn't. Tom admitted that to himself (in the novel) after Sonny was killed. And, as we've discussed, Michael needed a totally legitimate Tom, unsullied by war, to front for the family in legitimate Vegas. But I really don't understand why he kept Tom out of the Roth negotiations while letting Rocco and Neri into them.

Keeping Tom out of the Roth situation kept intact that which you have already stated: Tom stays clean. However, it was this arrogance and desire to be a Lone Ranger that I believe caused him to fail in taking Roth out in Cuba. I personally feel that if he includes Tom in that whole ordeal, Roth doesn't "see the New Year" as Michael originally planned. His arrogance jumped up and bit him in the ass right there.

I agree Tom should have been involved more. But like Turnbull already said, he did need to be clean for the Family. Also, I think Michael did have a pretty good idea it was Roth, but maybe not 100%. Even if he did, he was not sure who betrayed him, and spreading information at that point would not be smart.

You would, wouldn't you Tom_Hagen_Fan

That scene was perfectly played but it always bothered me just a bit. Perhaps it's because I'm the oldest in my family but why should Tom have been so desperate that Michael accept him personally as a brother?

I mean Tom was what, eight or ten years older than Michael?
I can see Tom giving Michael all the professional courtesy (and more) due to a boss but why would he have lost too much sleep over whether his adopted kid brother really liked him or not?

It just seemed a little too puppy-dog like for a cool customer like Tom.

Maybe he still blamed himself (and thought Michael did as well) for Sonny's demise???

A guess is that Tom, who came from a broken family and had no family at all when Sonny found him, really valued and wanted to be part of the family, not just consigliere or lawyer. And with Sonny gone, and Michael so cold to him even early on (attest the Dreaded Corleone Stare in the flashback scene at the end of II), Tom was feeling insecure.

Maybe Tom was really hungry for family love. Just because he didn't have a family.
By the way, we never get to know anything about the relationship between Mamma Corleone and Tom. This could be worth a new thread...

Mike used Tom just like he used everyone else. To me, that's it. Otherwise, Tom meant nothing to him.