Well, one GP isn't going to totally end a war. A meteor shower can take out 1/4 of a town, but a player still has resouces, and from what i've seen, the meteor shower seems to be best used against fortifacations, not units, so one could still defend themselves with units. (units can always run away from the meteors.)
The opposite of love is not hate, it's indifference.
The opposite of art is not ugliness, it's indifference.
The opposite of faith is not heresy, it's indifference.
And the opposite of life is not death, it's indifference.