So. This is how it’s gonna’ be, huh?

Iran’s anger over a new U.S. sanctions measure may have been behind its move to interrupt talks with world powers over how to implement last month’s breakthrough nuclear agreement, two diplomats said on Friday. …

Iranian Deputy Foreign Minister Abbas Araqchi told the semi-official Fars news agency on Friday: “We are evaluating the situation and Iran will react accordingly to the new sanctions imposed on 19 companies and individuals. It is against the spirit of the Geneva deal.”

One diplomat said the Iranian delegation suddenly announced late on Thursday evening – hours after Washington made its decision public – that it was returning to Tehran.

The Iranians said “they had received instructions from Tehran to stop the discussions and fly back to Tehran,” the diplomat said. “It was quite unexpected.”

“My understanding was that this was not to do with a specific problem in what they were talking about but actually their reaction to moves in the U.S. on sanctions,” the diplomat said, adding that the hope was that it was a temporary problem.

Yesterday, in an effort to reassure the bipartisan group of lawmakers still focused on passing an additional round of sanctions on Iran and to deter them from doing so, the White House announced that they were going to crack down on a list of companies and individuals flouting the sanctions already in place; “Today’s actions should be a stark reminder to businesses, banks and brokers everywhere that we will continue relentlessly to enforce our sanctions, even as we explore the possibility of a long-term, comprehensive resolution of our concerns with Iran’s nuclear program,” Under Secretary for Terrorism and Financial Intelligence David S. Cohen said in a statement announcing the designations. Evidently, the Iranians did not take well to that, and pulled their officials out of the talks in Vienna going on this week that were meant to simply outline the possible ways in which the interim deal worked out last month could take effect.

The oh-so-delicate conditions upon which this entire deal appear to hinge are almost enough to make you wonder about Iran’s seriousness in winding down their nuclear program over merely achieving sanctions reductions, no?