My favorite part of checking out Game Jam submissions is discovering fresh concepts I've never seen before. Your entry is one such game. Essentially you play as an arms dealer trying to keep the war going in perpetuity, arming both sides. Super fresh idea, right in line with the theme, I love the art, this is an excellent submission.
My advice for developing this concept further would be to make the house of cards you are building grow increasingly unstable. Maybe every card you play speeds up the battle by 1%. Or maybe you just have one deck and have to play or discard cards carefully to not overly bolster one side.
Anyhow, I really enjoyed playing your entry. I hope it gets the attention it deserves!