Interview Heinz Gärtner with Al Jazeera, September 9, 2019
Iran is withdrawing step by step from the Nuclear Agreement (JCPOA). It does so openly and not in secret. According to the paragraphs 26 and 36 of the agreement, Iran has the right to reduce its commitments if other parties to the agreement have violated it. Since the US abandoned the agreement last year, the sanctions imposed by the US on Iran remained not only in place but have been ratcheted up what is a clear violation of the agreement. Economically, it is understandable that Iran wants to put pressure on the other signatories to lift the sanctions. The idea is that the Europeans compensate the losses of the US-sanctions and also put pressure on the US to return to the JCPOA. These tactics will not work because the Europeans themselves are afraid of US-secondary sanctions.
Politically, it is unwise of Iran to phase out its commitments to the agreement. If Iran leaves the JCPOA, it will be blamed for the collapse of the agreement. Also, the historical narrative will make Iran responsible for it, in spite of the fact that Iran had the legal right to do so.
In addition, Iran cannot claim credibly that it does not want to acquire a nuclear weapon and at the same time scare the Europeans that it might go in this direction if the Europeans do not meet its requests. Eventually, this contradiction will be visible and will do harm to Iran.
However, if Iran returns to its commitments it will be judged as the morally stronger power. To underline its non-proliferation commitments, Iran could sign and ratify the Treaty on the Prohibition of Nuclear Weapons.