In July 2015, eight parties - France, Germany and the United Kingdom, together with the European Union and China, Russia and the United States on the one side, and Iran on the other - adopted the Joint Comprehensive Plan of Action (JCPOA), better known as the Iran nuclear deal. Under the agreement, Iran accepted limits to its nuclear programme in return for sanctions relief. Hailed by some as a diplomatic achievement, detractors - both in the US...