[Rimbaud]

Just a quick point on what you are saying: I believe what you are driving at is Tolkien's understanding of the importance of trust in any genuine friendship.

A good example would perhaps be a case where a good friendship did not develop; let's use Boromir and Frodo as an example. Despite being (in markedly different ways) fine individuals - who, with some irony, ultimately are vindicated of the same flaw - they never in life create such a bond as you describe above. The key reason for this, would surely be the lack of trust, despite there being mutual respect between them and other qualities necessary for friends.

The reason Sauron and Saruman could never truly be 'friends' is the same lack of trust. On that matter, however, I do not think Tolkien ever intended for this realtionship to be considered any more than the sum of its parts - constituents that comprise convenience, greed and mutual loathing of the status quo. I think it unlikely that either character believed in any 'friendship', it was a marriage of convenience.

The friendships within the Fellowship are as you describe, rich and true, but perhaps more interesting would be the friendship between Gandalf and Saruman, prior to the former discovering the treachery of the latter. Could it really be termed a friendship?