The 2015 Iran Treaty Has Not Been Broken, by Jim Dunnigan.
The Americans abandoning the 2015 treaty was not a violation of the treaty because the U.S. used a provision of the treaty to exit the deal. The American president, as required by the treaty, had to regularly certify to the American legislature that the terms of the treaty were being met. For a number of reasons, including the recent Israeli revelations, the most recent certification was not made and Iran was accused by the U.S. of all sorts of bad behavior.
The other nations that signed the treaty say, for now, they will continue to support the treaty. This is important for Iran because it means they can still sell their oil and import a lot of industrial and consumer goods.
Longer term the situation is not so good. The Americans and Israelis are on a roll and intent on exposing much more Iranian bad behavior. In some cases, Iranians will be a source, but in all cases, Iranians will be consumers of such news and that weakens the control the Iranian clerics have over the Iranian government.
President Rouhani has offered to continue the 2015 treaty with the other participants if those countries, especially the European ones, can ensure that Iran does not suffer from the American withdrawal. This puts the Europeans on the spot because they have to consider this proposal at the same time more and more evidence of Iranian bad behavior surfaces. This is largely because Israel is allowing the European nations to send their own intel and nuclear weapons experts to examine the huge trove of Iranian documents. So far these documents have been toxic for Iran and any Iranian claims to never having had a nuclear weapons program.