The situation is as follows: - I am on one continent with the only other civilization on it being my vassal. - The largest opponent occupies another continent. - To win by domination I need to either conquer my entire continent or sail to the other one to try to overcome that large opponent. - It would be easier to finish my vassal, however I cannot find a way to declare war on him. Whatever I request from him, he gives without a word. Any advice? Thank you.