"Fought well you have, my old padewan" - Yoda to Dooku in AOTC

By ROTS, the two have come to realize that they may even have to go against their own morals and the Code, to stop the Sith.

Right, but I am not talking about them killing Sith, I am talking about them letting each other come to harm. In the book, Obi-Wan and Yoda are talking about Anakin, and how he is a fiercely loyal friend -- to the point where he is so attached to those he loves and cares about that he will go against the Code to do things for them. Obi-Wan tells Yoda that while he would sacrifice Yoda's life without thinking about it, if the need arose -- as he should, Yoda affirms, saying that he would do the same -- Anakin would not. This fierce attachment is a concern to them.

Take care,
Sojourn