That's a very narrow definition of "aggressor" you're working with there. The aggressor is the one whose aims of conquest force the conflict.
I don't accept your idea of an aggressor because that would make european colonialism aggressors and would make the US the aggressor against the indians.
But while we are at it, I see that Israel took the west bank by force and intends to keep it. Further, Israel has always wanted the west bank and Jerusalem. Even by your definition, that makes them the aggressors in the 6 day war.