After the 'Green Movement' in Iran, opposing the dominance of the Shia clerics and their Revolutionary Guards over the parliamentary system, was brutally crushed by the security services in 2009-10, major protests were for a while quelled. Although the revolutionary wave of 2011 across the Arab world stimulated some expressions of dissent in Iran, widespread popular unrest across much of the country did not erupt until December 2017-January 2018. These protests were a prelude to the extensive demonstrations in most parts of the country in November 2019, which were primarily a response to increasing economic hardship. This unrest was due partly to the re-imposition of international economic sanctions, after President Trump destroyed the nuclear deal negotiated under Obama. As a result, the Iranian government announced a further cut in economic subsidies and a rise in fuel prices in mid-November 2019. Other reasons for demonstrating included anger at corruption and desire for political change. Protests occurred in 29 of the 31 provinces in Iran and an estimated 100 cities, and included ethnic Arabs and Kurds from border provinces. The social composition of the 2019 upsurge was broader than in 2017-18, but students, workers and the poor were dominant. The regime responded ruthlessly, and shot hundreds of protesters.
Iran is sometimes mentioned in the context of a 'Second Arab Spring', and some protesters in November 2019 did express solidarity with those in Iraq and Lebanon resisting the role of Iran in their internal politics. However, popular anger erupted onto the streets primarily in response to Iranian issues, as in January 2020, when mass protests occurred over the accidental shooting down of a Ukrainian passenger jet by the Islamic Revolutionary Guards.
The references below cover the 2017-18 protests, November 2019 and January 2020, but also include some analysis of the background of the regime created after 1979, the Green Revolution and its aftermath.