Also, out of curiousity, what is the evident jealousy between Tom and Micheal that you refer to? I can see it too in a way but I'd like to know what led you to that conclusion and see if they are the same factors that made me consider this.
I think that Michael was jealous of the close relationships that Tom had with Vito and Sonny. I also think he blamed Tom, rightly or wrongly, for Sonny's death. And from flashback at end of 2, Michael didn't appreciate Tom discussing Michael's life with "their" father.
So when Michael took over he was a little colder to Tom than needed to be-putting Tom on the constant defensive- which allowed Michael to manipulate him more. I buy that Tom had to try to remain on good terms with someone who obviously had no problems having him murdered if it came to that.
I'm not sure that Tom, who had already and been accepted as a full brother/son by all of the other Corleones, would have been so needy of Michael's approval on a personal level.
Interesting that you say Micheal may have blamed Tom for Sonny' death - a good point that i'm inclined to probably agree with to an extent.
The factors I think of with regards to the jealousy between them, however, is largely to do with Micheal joining the family business. I sometimes believe that Tom didn't
want Micheal to join the business as it would have led to him being 'stepped-over'. Tom and Micheal shared the same good business acumen and Tom perhaps realised they may end up fighting for the same role.. A few events in the film which make me think this are:
* When Tom say's 'maybe we shouldn't get Mikey involved' when Sonny ask him to visit Luca Brasi's house
* The look on Tom's face when Micheal mentions his plan to kill Sol and Mac, everyone else laughs it off but Tom seems concerned/wary
* Tom's face when Micheal ask him to step outside when meeting with Ola, there seems to be a look of rejection
The relationships between all the brothers is fascinating. Jealousy, one-upmanship, bitterness all combined whilst fighting for thier fathers approval. One of Vito's greatest challenges must have been to manage the relationships between his children, whilst being head of the most powerful mafia family. He must have turned in his grave when Fredo was killed.