[The Saucepan Man]

I have always felt uncomfortable with the quote referring to Gandalf being the only one to succeed in the 'mission' of the Istari, since it devalues those others who were sent but who did not (necessarily) fail in the same way that Saruman did. I am reluctant, for example, to accept that Radagast 'failed', even though he might not have been instumental in the defeat of Sauron in the same way that Gandalf was. It seems to me, therefore, that the distinction suggested by Boromir88's post is an important one. While Gandalf may have been the only one to succeed in their 'general' mission, namely to counsel and guide the Free Peoples and thereby assist them in bringing about the defeat of Sauron, I like to think that Radagast succeeded in his own 'personal' mission, to care for the flora and the fauna of Middle-earth.

I also like to think that Alatar and Pallando succeeded in their own way, possibly by counselling some Men of the East against allying themselves with Sauron, and thereby depleting the forces available to him. Although that is pure speculation and more difficult to square with the statement that Gandalf was the only one who succeeded.

Of course, Gandalf was (as far as we are aware) the only one to receive a 'turbo-boost' (following his 'death' in the fight with the Balrog of Moria), which seems to have allowed him to use his powers more directly, and with more devastating effect, thereafter.