"On May 8, 2018, President Donald Trump announced that the United States would cease implementing U.S. commitments under the 2015 multilateral Joint Comprehensive Plan of Action (JCPOA) with Iran. He indicated that, by the end of a 'wind down period' (by November 4, 2018), all U.S. sanctions in place prior to the JCPOA--which target foreign firms that conduct transactions in all of Iran's core economic sectors, including energy, banking, shipping, insurance, manufacturing, and hard currency trading--would go back into effect. These include sanctions on 'petroleum-related transactions' and transactions by foreign banks with Iran's Central Bank. Several hundred Iranian and third country entities will again be designated by the United States as sanctioned entities, meaning that foreign firms that transact business with these entities could face exclusion from the U.S. economy and financial system."
CRS In Focus, IF10916