After we agreed to the armistice in Korea in 1953, Red China turned over many of the captured US weapons to the Viet Minh; the French were furious that we’d made that deal that ended up costing them dearly (while they fought a war they hadn’t even wanted; we convinced them to fight it).
We never should have allowed the French back into Indochina after WWII, would have saved us a lot of grief.