Looking at the record from an objective viewpoint, Iran has indeed failed to cooperate with international nonproliferation agreements regarding weapons of mass destruction. Other major problems revealed by the EU and the US:

• There do not appear to be any meaningful AML or CFT controls in Iran.

• Front companies are routinely used to hide illicit activities of the state.
  

• Major state-owned Iranian banks are involved in supporting prohibited nuclear weapons and missile programmes.

• Financial and military assistance is being supplied by Iran to Hizballah, a designated global terrorist  organisation.
  

• There are close ties to Venezuela involving illicit Uranium sales to Iran, and missile technology purchases from another nation deemed to be a rogue, the Democratic Peoples Republic of Korea (North Korea), to advance Iran's missile programmes.

Whilst the US is the only major power sanctioning Iranian financial institutions and companies, a FATF NCCT designation would discourage those members of the global financial community who still trade with Iran from continuing the relationship. US sanctions, frankly, have not deterred Iran from the development of prohibited nuclear weapons, and missile delivery systems.

Whilst some prominent European banks have ceased financial intercourse with Iran, several others maintain relationships, as do a number of banks located in the Middle East. Would those banks terminate their business with Iran, when faced with a FATF sanction? We cannot say, but they would certainly look closely at the increased risks of a continuing relationship.

On the other hand:

• Would an NCCT designation isolate Iran, much as happened to North Korea in the aftermath of the Banco Delta Asia scandal? Would this result in hardship to the average person, but not affect the powerful elite?
  

• Would it hurt the economies of those Middle East and Asian countries that it currently trades with?
  

• Would not indirect financial commerce, through third countries, take the place of direct contact?
  

• Would the counterfeiting and distribution of US currency, on a large scale, or other acts of retribution occur as the result?

Whichever side you find yourself on, the matter deserves further study before any knee-jerk action is taken. Since it may bring the region to the brink of war, the benefits must be carefully weighed against the possible problems it might create.