Alliance war and capitulate?

[alrak]

Hi,
is it possible to capitulate to an alliance as single player? Or even the whole alliance?
One of my alliance members gets always attacked in an alliance war by the same player (they declared us alliance war and we get attacked by only one player --> the others are much to strong for us). So what can he do? The attacker has allmost 2x points.

Hope you all have some good ideas

thanks