Enemy Within introduces the concept of medals -- minor, customizable bonuses that you can bestow upon worthy soldiers from the barracks.
However, such medals are limited quantity - how do you earn more?
I believe that you earn one International Service Medal for every council mission undertaken, but I have no idea about how to earn the "Defender's Medal" that I've already run into. (Perhaps something to do with the rookies dying? I expect a lot of rookies to die. C'est la XCom)