Both the United Nations and the European Union formally reimposed sanctions against the Iranian regime last month, due to its secretive nuclear program and its failure to comply with treaty obligations. Iran and its allies responded defiantly, but the sanctions serve to isolate the rogue state from the rest of the world.

The U.N. Security Council approved the sanctions on Friday, September 19, just before the U.N. General Assembly’s annual meeting began on Monday. The U.N. sanctions took effect at midnight Greenwich time on Sunday, and the E.U. approved its own sanctions on Monday, September 29.

The U.N. sanctions prohibit member nations from furnishing Iran with weapons or anything that could aid their uranium enrichment or ballistic missile program. They also freeze Iranian assets in overseas banks, impose a travel ban on Iranian officials, and authorize governments to inspect cargo on Iran Air or Iran Shipping Lines.

Upon news of these severe sanctions, Iran’s currency immediately plunged to a new low (1.1 million rials to $1), raising domestic food prices and placing further pressure upon the country.

The U.N. originally imposed these sanctions on Iran nearly 20 years ago, between 2006 and 2010. However, the sanctions were suspended in 2015 as part of the Joint Comprehensive Plan of Action (JCPoA), the Obama-era Iran nuclear deal (during his first term, President Trump unilaterally withdrew the U.S. from the JCPoA, arguing that it was a bad deal). The suspension of these sanctions allowed the Iranian regime to access global financing and global markets, dramatically accelerating its secret nuclear weapons program.

However, the JCPoA did include a “snapback” mechanism, by which years’ worth of sanctions against Iran would suddenly “snap back” into place, if one of the parties to the JCPoA believed that Iran was not fulfilling its obligations, which included opening its nuclear facilities to U.N. inspectors from the International Atomic Energy Agency (IAEA) and not developing nuclear weapons.

Here is where the IAEA takes center stage. Ever since Hamas’s October 7 attack on Israel launched a hot war between Israel and Iranian terrorist proxies, the IAEA’s quarterly reports had noted the dramatic expansion of Iranian stockpiles of highly enriched uranium (enriched to 60%), which is not required for nuclear power generation and can be transformed into weapons-grade uranium (enriched to 90%) in a matter of days. By May 2025, IAEA inspectors found, the Iranian regime had acquired enough enriched uranium to make 10 nuclear bombs.

On June 12, the International Atomic Energy Agency’s (IAEA) 35-nation board officially voted for the first time to find Iran in non-compliance with IAEA oversight, citing violations dating all the way back to 2003. The resolution was brought by four Western nations, the U.S., the U.K., France, and Germany. The IAEA board approved it 19-3, with Russia, China, and Burkina Faso voting in opposition, 11 nations abstaining, and two nations casting no vote at all.

Although the U.S. had withdrawn from the JCPoA, the U.K., France, and Germany were all still parties, and they signaled their intention to trigger the sanction “snapback” against Iran unless the regime changed its course.

The Iranian regime did not change course after the IAEA’s vote of censure. It threw out IAEA inspectors and announced that it would expand its enrichment capacity even further by opening a secret, third enrichment site it had not disclosed to inspectors — effectively admitting to yet another violation of its obligations. It even threatened to withdraw from the Nuclear Non-Proliferation Treaty (NPT), a decision for which North Korea provides the only precedent. These acts of defiance prompted Israel (and ultimately the U.S.) to bombard the fortified facilities, setting back the secret Iranian weapons program for as long as possible.

Iran did not allow the IAEA to resume inspections until Friday, after the vote to snap U.N. sanctions back into place.

In August, the U.K., France, and Germany asked the U.N. Security Council to reimplement sanctions, arguing that the Iranian regime had violated “the near entirety of its JCPOA commitments” and had failed to provide credible commitments to fulfill them. This declaration, coming a month before the U.N. General Assembly, gave Iran 30 days to respond or find a diplomatic solution, which failed to materialize.

The reinstatement of Iranian sanctions came just in time, as the sanctions against Iran were scheduled to expire permanently on October 18, 2025, along with the JCPoA.

Shortly after the U.N. Security Council reimposed sanctions on Iran, the E.U. did likewise. On Monday, September 29, the European Council “agreed to reimpose” further sanctions suspended by the JCPoA, including a ban on oil exports, the sale of equipment used in the energy sector, the sale of precious metals and stones, and the sale of certain software and naval equipment. The E.U. also reimposed its freeze on Iranian bank assets (whether of Iran’s central bank or its various commercial banks) and transit restrictions on Iranian cargo flights.

The only move Iran did prepare at the U.N. was a last-minute effort on Friday, September 26, to postpone the U.N. sanctions by another six months. Although the move was led by China and Russia, it failed in the U.N. Security Council in a 4-9 vote with two abstentions (Algeria and Pakistan voted with China and Russia).

Despite the official passage of U.N. sanctions, Russia and China are not likely to comply. Russia already faces extensive sanctions due to its invasion of Ukraine, and China calculates that it is too important to face any real penalties. Both nations already rank among Iran’s foremost trading partners, with Russia and Iran maintaining a booming trade in weapons, while China buys Iranian oil at a discount.

Russian Foreign Minister Sergei Lavrov even went so far as to publicly defy the Security Council’s decision, declaring that the sanctions snapback was “unlawful” and “cannot be implemented.” On Friday, Russia signed a $25 billion deal to build four nuclear power reactors in Iran.

The sanctions decision also received predictable condemnation from Iran. “The United States has betrayed diplomacy, but it is the E3 [Britain, Germany, and France] which have buried it,” Iranian Foreign Minister Abbas Aragchi spat in his speech before the U.N.

On Sunday, the Iranian foreign ministry urged countries to ignore the U.N. sanctions, arguing, “The three European countries, under U.S. pressure and provocation, initiated the so-called #SnapbackMechanism despite their own persistent and significant failure to fulfill JCPOA commitments, amounting to a ‘gross non-performance,’ and have exploited the dispute resolution process.”

Iranian President Masoud Pezeshkian rejected a U.S. offer to hand over its entire stockpile of enriched uranium in exchange for a three-month exemption from sanctions, describing the deal as a “noose around our neck.” If the threat of sanctions is a noose, what is the implementation of sanctions? And why would Iran willingly accept such economically fatal sanctions to maintain nuclear stockpiles unnecessary for civilian energy production?

Meanwhile, Israel’s Foreign Ministry celebrated the sanctions on the regime that wants to exterminate the world’s only Jewish-majority state in a nuclear holocaust. “The goal is clear: prevent a nuclear-armed Iran,” it wrote. “The world must use every tool to achieve this goal.”

As always, the Trump administration remains prepared to back up words with actions — as Iran learned the hard way this summer. “The Security Council’s decision on September 19 — reaffirmed on September 26 — to restore these restrictions sends a clear message,” said the U.S. State Department. “The world will not acquiesce to threats and half measures — and Tehran will be held to account.”