What I mean is that the player can send warships to the trader pool in the same way he can send tradeships (as it is now). He can assign them as "privateers" which hunt down and destroy/plunder enemy traders. This should not be a declaration of war to this empire, because they are privateers like Sir Edward Drake.
Additionally for protection of its own traders an empire can also send warships to its own trader pool and designate them as "escort". The more escorts you have the better your traders are protected. I dont know the exact formula how to calculate this all. Maybe the main focus for success of privateer/escorts should be not only weapons but more speed of a ship. Maybe you get every turn or every few turns a message which tells you what happened with your traders/escorts/privateers. (eg. damage and loss of privateers/escorts/tradeships, loss of money or whatever) Important is that this should not add to the "micromanage" level of the game, so for this the fights in the trade pool should have an automatic mechanic and not be fought out on the tactical map.Why?
-Fun: Because it could be a fun subgame to damage the enemy without going necessarily going to war with him. (of course you should be able to do this when you are at war with the enemy too)
-Multi-role for Warships: it makes more use of idle warships in peacetime.
-Rebuild Tradeships: you have to construct lost tradeships from time to time which is not the case now.
-Technology: you could introduce special modules which helps tradeships to escape their privateers and vice versa.
-U boat: if you make it clever you could create a "uboat feel" which could give a player the impression of beeing a beleaguered England in WW2.
-Monsters & Pirates: the game could additionally autogenerate from time to time pirates and space monsters which populate the trade pools and plunder/eat your ships there
Attacking tradeships in the pool is probably a more intutive solution of how pirate behave than just guarding planets as it is now.
