I'm thinking of a POW game mode where one side is tasked with freeing the POW soldiers, while the other side must defend a prison in a somewhat asymmetrical warfare setting. This is almost like terrorists (holding hostages) vs. counter-terrorists, and it seems to be a very well received game mode, at least from other titles and in concept.
The Historical Backstory...
One historical reference has to do with the US fighting alongside the German Wehrmacht, against the German SS soldiers at Castle Itter located in the Alps in 1945 (the only known occurrence in WWII where German and US soldiers fought together!). The mission was to rescue prisoners at the Austrian castle, who were very high profile individuals including ex-prime ministers, former military men, and celebrities. The entire story is bizarre and intriguing and it would make for a great War Story (or at least a multi-player mode, or a co-op mission).
As another historical reference in WWII, Amiens had a prison camp and there was a major air raid (the Amien Raid) to free resistance fighters. No foot soldiers, per se, were sent in, but perhaps there were French resistance fighters there to coordinate the prisoners' escape. In any case, a BFV version of Amiens might be a nice encore map to see.
The Mission...
The attackers start with a fixed number of players with little to no reinforcements. If the attacking team reaches and frees the POWs, then those are your reinforcements and you can spawn from prison (or they're merely NPCs, or they remain as NPCs until you respawn). Now, the attackers and POWs have to escape and reach a boundary for extraction. Since the POWs have intel and/or are VIPs, if all of the prisoners die, then you lose the game.
Just throwing some ideas out there. Any thoughts?