Donald Trump's withdrawal from JCPOA ("Iran Nuclear Deal") poses many problems for everyone, including both the U.S. and Iran. The biggest problems for Iran are the economic crisis threatened by the loss of foreign investment and the currency crisis threatened by denial of access to the dollar denominated banking system, a vulnerability demonstrated by the Iranian rial's 12.5% plunge last Saturday. The degree to which it can avoid the first depends on the willingness of international actors to resist American pressure, but the latter can be easily sidestepped if Iran will just apply modern...