The Wall Street Journal | Asa Fitch and Josh Ulick: U.S. sanctions on Iran date to 1979, when the Carter administration froze Iranian assets in response to the Iran hostage crisis, in which 52 Americans were held for more than a year at the U.S. Embassy in Tehran.

Sanctions pressure rose in the late 1990s and early 2000s under the Clinton and Bush administrations, responding to Iran�s advancing nuclear program and its support for Hezbollah and its support for Palestinian militant groups fighting Israel.

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