The latest dispute to arise between the two states probably won’t be as ugly as that, but it’s not looking good at the moment. Efforts to clean up the Chesapeake Bay, the so-called “blueprint” plan that Maryland, Pennsylvania and Virginia have agreed to follow, have run into trouble. To put it simply, the U.S. Environmental Protection Agency — the police officer (or perhaps probation officer) that was supposed to make sure that the three states that are the primary sources of pollution into the nation’s largest estuary were cleaning up their act as promised — is missing in action. And that’s a problem. A big one.