I think that if the Jedi had protected the Republic, there would be no Darth Revan and Darth Malak. No Malachor V disaster. No extinction of the Jedi. Had they all entered, had the Council not feared the future, Revan would have never been. There would be no division in the Jedi, the Madalorians would've fallen quicker, more lives would be saved, and there would be no return of the Sith. If the Council chose to protect the Republic, rather than the Jedi, the galaxy would be safe. There would of course, be no KoTOR video game. :D
Foolish, blind Jedi. You're there to protect the Republic, not yourselves. A Jedi's life is sacrifice.