President Trump declared his intention not to recertify the Iran nuclear deal in a forceful speech on Friday. But the rationale he provided includes several misleading or incomplete statements about the terms of the deal, what he considers a violation of the agreement and Iran itself. Here is an assessment.

Mr. Trump gave an incomplete account of Iranian history.

“Iran is under the control of a fanatical regime that seized power in 1979 and forced a proud people to submit to its extremist rule,” Mr. Trump said, referring to the Islamic Revolution. Clerics led by Ayatollah Ruhollah Khomeini overthrew the monarch that year and established an Islamic republic. His successor, Ayatollah Ali Khamenei, is currently the supreme leader of Iran.

Mr. Trump then listed the 1979 Iran hostage crisis, Iran’s sponsorship of terrorism and its support of President Bashar al-Assad of Syria among other examples of the country’s “hostile actions.”

All of these actions are undoubtedly hostile, but they require more context, said Abbas Amanat, an Iran scholar at Yale University, who added that the 1979 revolution was a popular movement and that the government, though repressive, has been moderating.