Original Coverage & Source Attribution: legis1.com
Why It Matters
U.S. sanctions on Iran are arguably the most extensive the United States maintains on any country, with thousands of persons designated, according to a new Congressional Research Service (CRS) report. The report traces how U.S. sanctions on Iran have evolved from the 1979 hostage crisis through the second Trump administration’s maximum-pressure campaign, and it notes that successive administrations have characterized the effects of sanctions on Iran’s behavior in different ways.
On Feb. 4, 2025, President Trump signed a National Security Presidential Memorandum directing a “robust and continual sanctions enforcement campaign” to deny Iran and its proxies access to revenue. After a U.S.-Iran memorandum of understanding collapsed amid renewed fighting in July, the Trump administration announced Operation Economic Outcast in August, aiming to “sever every economic lifeline that sustains this tyrannical regime until Tehran stands alone.”
The Big Picture
The report describes a layered legal framework that blocks Iranian government assets in the United States, bans nearly all U.S. trade with Iran, and prohibits foreign assistance and arms sales, with authorities covering Iran’s energy, financial, shipping and aviation sectors as well as the Supreme Leader and the Islamic Revolutionary Guard Corps.
The first Trump administration cited deteriorating Iranian economic indicators after reimposing sanctions in 2018, but the report notes Iran “has pursued those activities amid U.S. sanctions and their economic costs” and that its defense budget has “fluctuated, sometimes apparently linked” to the economic impact of sanctions. The report also says U.S. sanctions may create incentives for Iran to expand economic and military ties with China and Russia, with China serving as the main purchaser of Iranian oil.
The 119th Congress has enacted one Iran-sanctions measure: the Lindsey O. Graham Sanctioning Russia and Iran Act of 2026 (P.L. 119-111), whose sole Iran provision extended the Iran Sanctions Act of 1996 sunset from 2026 to 2031. The Enhanced Iran Sanctions Act of 2025, which would authorize additional sanctions, passed the House and was referred to the Senate Foreign Relations Committee on March 17. The Iran Sanctions Relief Review Act of 2025 and the Maximum Pressure Act, which would alter the conditions under which the president may waive or lift sanctions, remain at the Introduced stage in the House.
The Bottom Line
The Enhanced Iran Sanctions Act of 2025 has been before the Senate Foreign Relations Committee for more than seven months with no recorded action. If the United States and Iran were to conclude a nuclear agreement, the Iran Nuclear Agreement Review Act mandates a 30-day congressional review period during which the president may not waive or lift statutory Iran sanctions. The report says Congress may consider whether sanctions have advanced U.S. policy goals toward Iran and whether additional authorities or designations would change Iranian behavior.
