Seyed Hossein Mousavian (Persian: سید حسین موسویان, born in 1957 in Kashan) is an Iranian policymaker and scholar who served on Iran's nuclear diplomacy team in negotiations with the EU and International Atomic Energy Agency.

His family had close ties to the Motalefeh, a religiously oriented revolutionary movement that dated back to the early 1960s and was eventually absorbed into the Islamic Republican Party (IRP).

[3] During the 1980s, Mousavian played a major role in what he later described, in a 2012 book, as “Iran's humanitarian intervention to secure the release of Western hostages in Lebanon.” However, the hostage-takers (Hezbollah), had acted on instructions from the government in Tehran.

[4][5][6] After the issuance of the arrest warrant for the intelligence minister, which Mousavian described as an insult to the entire population of Iran,[7] Iranian news agencies made veiled threats against Germans abroad.

[8][9] The US State Department spokesman Nicholas Burns said the court ruling "corroborates our long-held view that Iran's sponsorship of terrorism is authorized at senior levels of the Iranian government.

[19] Mousavian's team was replaced shortly before the election of Mahmoud Ahmadinejad as president in 2005, in tandem with Supreme Leader Ali Khamenei's announcement that Iran would resume enrichment activities.

[20] Mousavian was arrested and briefly jailed by the Ahmadinejad administration in 2007 and publicly accused by the president of espionage for allegedly providing classified information to Europeans, including the British Embassy, before being cleared by the judiciary.

[21] There was speculation that his arrest was part of a factional struggle between Ahmadinejad and a triumvirate of his opponents: Akbar Hashemi Rafsanjani, Mohammad Khatami, and Hassan Rouhani, of whom Mousavian was considered an ally.

However, the third of those judges had sentenced him to a suspended term of two years in prison and to a five-year ban from official diplomatic posts because of his confessed opposition to President Ahmadinejad's foreign and nuclear policy.

[26][27] The House Committee on Education and the Workforce announced on November 16, 2023, that Princeton University is the subject of an investigation over the role of its controversial academic Mousavian, a former Iranian regime ambassador to Germany.

Mousavian expressed deep concern about developments in Iran after that country's 2009 presidential election but continued "to press for the U.S. to engage Tehran in a bid to reduce regional tensions," according to a 2010 article by Jay Solomon in the Wall Street Journal.

"[4] Mousavian dismissed as "politically motivated" the conclusions of a November 2011 report by the International Atomic Energy Agency (IAEA) that suggested "possible military dimensions" to Iran's nuclear program.

[28] Writing in National Interest in December 2012, Mousavian questioned the assumption by Western powers that "the best hope of altering Tehran’s nuclear policy and halting its enrichment activities" lies in "comprehensive international sanctions and a credible threat of a military strike."

[32] Reviewing Mousavian's 2012 book, Iranian Nuclear Crisis: A Memoir in the Wall Street Journal, Sohrab Ahmari said that although the book “is billed as a memoir,” it is more of “a diplomatic brief, complete with awkward bureaucratic prose and key sections stippled by bullet points.” Ahmari drew attention to “the endnotes, where an editor felt obliged to acknowledge where the author parts company with the public record,” as in an assertion that Iran had fully disclosed the details of its nuclear activities to the IAEA.