Well there is a story with this fellow, he is so determined to get revenge on the Century about what they did to there world.

Sometime the Century took there world, when they where growing and the Centauri used the Narns as slaves, so G'ka will try anything to get the upper hand on them.

He also gave the humans advanced weapon's during the Earth/Minbari war to help in the battle and the Century did not like that. They did not want the Narns to use the war to establish closer ties with the humans.

So a personal war normally goes on with G'ka and Ambassador Londo. The station did stop some wars from happening again.