This really deserves a link here: RS Roundtable: Suicide at the Council of Elrond:
An anniversary has recently passed. On October 25, 3018 Third Age, Elrond Half-elven, son of Eärendil of the line of Thingol, bearer of Vilya the great Ring of Power, made a critical decision for his people.
Rather than allow the last remaining outposts of the Elves at Imladris and Lothlórien continue without disruption from the outside world, he chose to invest the Elves in a grand global fight to rob Sauron of his power permanently, in the process destroying the Rings of Power of his own and Galadriel’s. At the Council of Elrond, a Fellowship was constructed, representing Elves, Men, Wizards, Dwarves, and Halflings, all united by a supposed common cause.
But where are the Elves now? All gone West. Was this great act of foreign policy by Elrond a self-destructive act? Would Elves not have been better off allowing Sauron to remain, acting as a counterweight to the Men, and preventing Men from being an undisputed hyperpower in Middle-earth?