While tensions between Iran and the United States have escalated, Europeans have implemented a special purpose vehicle — a payment channel set up to facilitate trade with Iran and avoid US sanctions. Yet the special purpose vehicle, known as the Instrument in Support of Trade Exchanges, or Instex, hasn't satisfied Tehran. Iranian officials have compared Instex to “a car without gas.”
A year ago, the moderate government of President Hassan Rouhani probably would have gone along with the current version of Instex and given it more time to prove itself. That doesn't seem to be the case now. Instead, Tehran has become intransigent, enriching uranium beyond the nuclear deal cap of 3.67%, on its way to 4.5%.