Do you think that international Hegemony is possible?

Do you think that nations would ever agree to cooperate with a world government that does not have a specific nation's interests at heart, but rather the interests of mankind as a whole? Participating governments would relenquish most power to the Hegemony and become something akin to states in the world government. Militaries would have to be disbanded except for peacekeeping forces controlled by the Hegemony and borders between countries would be completely useless. Does anyone think that this is possible in the real world? It would be a gradual process with the Hegemony winning individual nations over one at a time.