Ever since the South Korean ship Cheonan went down last month, there have been questions about what caused the explosion. Did an exploding mine sink the ship? A human torpedo? What we know is that 46 sailors died. This tragedy is a chance to push diplomacy forward. If we had a U.S. ambassador in Pyongyang and one of their diplomats in Washington, we could push for answers. But we are still technically at war with North Korea. There could be thousands of mines in the waters around North Korea (like we have on the DMZ between the Koreas), but our militaries have no way of disclosing to each other where they are. It’s time to change that and prevent things like the sinking of the Cheonan in the future. Forty-six men lost their lives, and it didn’t need to happen.