Quote Originally Posted by Shadow
I don't think you can trade with countries that you are at war with but you can still trade with countries at war with each other.
I imagine then that rushers must have problem with securing decent revenue from sea trade as they are probably at war with multiple factions at the same time. Personally, I try to limit hostilities to one faction at a time and finish them completely before starting on the next. That seems to result in quite a health trade income.