It seems, from the first few games that I've played, that as soon as I go to war with a civ that is doing trade with me, I get a message instantly that trade route x is too dangerous to continue etc.
Now, this didn't happen straight away in GalCiv 1.
At least 2 trade ships had to be destroyed first but in this game the very act of attacking an opponent seems to render any trade route that's running between a planet of yours and theirs, too dangerous to continue.
Is this meant to be? I preferred it in GalCiv 1