Diplomacy of the Wastes is a uncommon Sorcery card from Fate Reforged (FRF), collector number 67. Current market price: $0.03 (foil $0.10), TCGplayer market prices via Scryfall.
Target opponent reveals their hand. You choose a nonland card from it. That player discards that card. If you control a Warrior, that player loses 2 life.