For a future patch or update I think Ironclad should create casulty records. When you or your enemy declare war Military Deaths, Civilian Deaths, Wounded should be recorded in a sort of stats counter section of the diplomacy page. Every ship (frigates and capitals, gunships and fighters) have a crew count, and even when taking damage personnel would get wounded or killed.

The idea is that a long, protracted war could have huge loss in life, Morale accross the empire could suffer. Planets that have seen extensive warfare might feel the devestation more than planets far from the frontlines.

Also, psychologically on the player themself, you might reconsider your attempt to invade the enemies territory if the consequences mean the collapse of your empire. Plus, You might feel a bit more connected to you empire if you know you just lost 1 million crewman in that last battle to take a planet. Just like the simple concept of naming your ships, it's all about immersion into the game- becoming personally invested in your empire.

This idea is an evolved spin-off from the end mission in Homeworld2. One of the most poignant moments is the defence of the Hiigaran Homeworld, when the Vaygr attempt genocide by using atmosphere deprivation missles. Every time a missle hit, millions on the planet would die. The attempted planetary destruction created an amazing sense of threat of annihilation and elevated the immersion of the game. Yet all it was is a simple number counter.