What is the effect of morale in the game.
Morale isn't mentioned in the manual at all.

It provides a bonus to all troops in you command radius. The troops with morale bonuses have a little white star near them and you can see the bonuses in their stats, so Combat might read 15+4 and Speed might say 10+2, meaning Morale is giving a +4/+2 bonus to Combat/Speed.