Germany took a city state that caused an emergency. Only two civs (including myself) accepted the emergency. A few turns later, I considered getting some help by asking other civs to Join Ongoing War. Every single one of them agreed to join our war for exactly 1 gold. Like 6 of them. It seems that regardless of if they wanted to join the emergency, they would have differing relationships with Germany. I can see them not agreeing to join the emergency in fear the accused would get stronger and then wanting to immediately join the war on principle, but that is questionable also. I can probably dig up a save if it will help.