This chapter looks at how the JCPOA corresponds to the EU's interests, analyzing them in their reverse order. It looks at how the agreement helps to strengthen the global nonproliferation regime by probing the various stipulations of the deal. The chapter takes stock of the EU's aim to remain united, both internally and across the Atlantic. It looks at different attitudes in Europe and the United States towards the use of force vis-a-vis Iran because the EU's diplomatic initiative did indeed avoid a war with Iran but instead others are raging in the region. Once the United States had joined the talks in 2006, the Europeans focused more on keeping a united international – that is primarily transatlantic – front than on worrying about their own disagreements. European and transatlantic unity persevered during the negotiations, but neither can be taken for granted any longer.