You retaliate by killing the people from the other faction. That's kinda how world pvp works. On PvP servers, the raid time can often be taken up just by the back and forth world pvp that happens fighting over the right to kill a world boss.
if you don't like it, you should be on a PvE server.
And then they wonder why there's no world pvp in this game, when the players on the pvp servers don't even know what world pvp is about.
You should go back and re-read the entire post before commenting.