I had an idea: the game should consider another military rating during the game: the Troop Rating. It is something totally alien to the actual military rating (that uses only ship attack/defences point), but should not be taken lightly.

The way I see it, your "troop power" should be the # of troops you actually have in transports x Soldiering. That way, you could measure up when alien civs are readying for an invasion, or they could measure when YOU are.

Troop Power should also be a good way to intimidate other civs. If your actual military power is higher than theirs, and your troop power outnumbers theirs 5-1, they should be more than affraid that you actually might destroy them.

Stockpiling escorted transports during peace time would become a new standard for civs to aquire "power". (Not to mention, they would also be much more effective when they declare war: they already have troops ready for the go)