The Iranian nuclear agreement was the result of a pressing domestic need. This paper discusses the factors that pushed Iran to sign a nuclear deal and argues that the circumstances under which Hassan Rouhani became Iranian president meant he had to achieve a political détente in foreign relations within 100 days in office. Moreover, this pressing détente had to address the issue of sanctions. The successive rounds of US and Western sanctions drained the “resistance economy” and pushed it to resort to “heroic flexibility in diplomacy” whose lines were drawn by Supreme Leader of Iran Ali Khamenei. This paved the way for a change in politicians’ rhetoric and performance vis-à-vis relations with the US.