In World War One, the Germans and the English stopped killing each other at Christmas and played a game of soccer. They they resumed the war. Ping-pong diplomacy helped open up the relationship between Communist China and the US. The combination of South Korean and North Korean female ice hockey players forming one team to play in the recent Winter Olympics helped make the breakthrough which led to the new kind of relationship between the two Koreas, and with the US. As we ponder the path from war to peace, and the path to avoid war in the first place, let us ponder the role of play. It is not to be underestimated.