Tom Clancy's EndWar

When selecting a match in Theater of War mode, you can see in the bottom left corner whether it is a defense or attack match. Opposite the colored picture of the faction will be written either the phrase “[Attacker]” or “[Defender]”. If it says "[Attacker]" next to your faction, then that's what you need for this trophy. Win 40 of these matches and you'll get it.