This achievement is possible to get. I just got it tonight. I believe you need to unlock both World War II Victory Medal and American Campaign Medal at the same time. This will work if you haven't already unlocked American Campaign Medal. When boosting this, make sure you use a different profile/account when you are not going for the achievements yourself. You will need a 48 hour pass or something similar. When it is your turn, use your profile/account, play Ranked Matches, Objective Airborne, and go through all 6 maps. Capture 2 flags and then capture the bigger one that needs 2 people to capture. Make sure nobody does anything that might put their score above yours.
After all 6 maps, you will unlock World War II Victory Medal, American Campaign Medal, and EAM Campaign Medal.
If you already unlocked American Campaign Medal, chances are you won't be able to unlock World War II Victory Medal.
Also, if you have already played some MP, figure out which map you haven't played on, and play that map last when doing your map rotation. Chances are that if you played on a map before, your team may have won, and if that's the case, you may unlock American Campaign sooner than expected, which will ruin Victory Medal.
Hope it helps.