You can actually combine your army with a trading Caravan and force it into battle regular battle. I had my Sovereign cloud walk onto the trading caravan and combined my armies together. Now this trading Caravan is a WAR CARAVAN.
Could you also make Capitar caravans not set the "There is an enemy if your territory" flag?) Or was it when you put your mouse over a Capitar trading caravan not active the attack mouse icon?
http://imageshack.us/a/img801/4562/vvmt.jpg
