With the ultimate aim of renegotiating a dozen unfavourable terms of the nuclear agreement signed in 2015, on 4 November, the Trump Administration activated the second tranche of sanctions against Iran, following those that came back into force on 6 August, which may have extraterritorial effects with significant repercussions for all those who do business with Iran and wish to maintain good relations with the USA.

The US sanctions primarily concern Iranian port operators and those in the shipping and shipbuilding sectors, the purchase of oil, petroleum products and petrochemical products, transactions by foreign financial institutions with the Central Bank of Iran, including the provision of specialised financial messaging services (SWIFT), the provision of underwriting, insurance and reinsurance services, and finally Iran's energy sector.

In addition to the Iranian flag carrier, Iran Air, more than 50 banks—representing almost all Iranian banks, their international and domestic subsidiaries—and 300 local or country-linked entities will be affected, having been added to the list of approximately 700 units designated under previous sanctions.

In the 180 days prior to 4 November, the United States conducted consultations with international partners to assess their adherence to the principles expressed in the Presidential Memorandum of 8 May. The result of this effort has materialised in the possibility granted to eight countries, including Italy, to continue purchasing Iranian crude oil for at least the next 6 months, without incurring sanctions and with the promise to commit to taking measures that lead to the total suspension of business with Tehran.

Studies by the Unione Petrolifera Italiana have shown that in the first 8 months of 2018, Italy imported 5.2 million barrels of crude oil from Iran, 10% less than in the same period of 2017, although Iran remains our third-largest exporter, accounting for 12.5% of total Italian oil imports.

The quantity of crude oil that may be imported daily is not yet clear. In addition to Italy, the largest European importer of Iranian crude, the other seven countries excluded from the sanctions are Greece—the only other exception among European Union member states—the top four buyers of Iranian crude (China, India, South Korea and Turkey), and Japan and Taiwan, thanks to the efforts made to reduce oil imports from Iran in the period between the first and second tranches of sanctions.

Following these sanctions, Goldman Sachs expects to see Iranian exports fall from 2.5 million barrels per day last spring to 1.15 by the end of the year.

The European Union has declared its opposition to the American sanctions and has announced that the EIB (the European Investment Bank), in collaboration with other European financial entities, intends to establish a series of instruments to facilitate legitimate financial transactions with Iran in permitted sectors. Some member states are already mobilising to create an instrument that appears destined to replace SWIFT, in order to allow payments to European companies operating in Iran and the purchase of oil, without incurring secondary sanctions. This instrument would appear to be a form of barter, or rather a "clearing" mechanism that would allow the price paid for oil purchases to be used to pay for legal exports to Iran under both US and EU legislation.