U.S. participation in the upcoming negotiations doesn’t appear to be premised on an expectation of Iranian veracity. If it were, President Obama wouldn’t send his secretary of state until Tehran had come clean about its past deceits. The exemplary behavior of South Africa’s often-mendacious apartheid government when it decided to go non-nuclear — total transparency about the militarization of its atomic program — isn’t expected from Iran. The clerical regime has already dropped the bar through its “facts on the ground” intransigence: more than 19,000 centrifuges built and a heavy-water plant nearing completion. Washington doesn’t want to go to war again in the Middle East, and the Iranians know it.