by Alessandro Spinillo, thinc.
On September 28, 2025, sanctions on Iran were reimposed, after the United Kingdom, France, and Germany (the “E3”) had triggered the snapback mechanism before the UN Security Council on August 28.
In accordance with Articles 10 and 11 of UNSC Resolution 2231 (2015), the reimposition applies ipso facto. No certification by the UNSC’s Presidency is required. It restores both the sanction regime and enforcement architecture under UNSC Resolution 1737 (2006) as they were in force on 14 July 2015, which is the date of signature of the Joint Comprehensive Plan of Action (“JCPOA”), later endorsed by Resolution 2231.
The snapback is self-executing; the UNSC’s Presidency, however, must issue procedural directions to revive its enforcing organs, namely the Sanctions Committee and the Panel of Experts under Resolution 1737 (and subsequent related resolutions, notably 1747, 1803, and 1929).
The Sanctions Committee consists of all 15 members of the Security Council, permanent and non-permanent. This is to say that it is automatically composed of current Council members; no separate appointment process is required, and a simple administrative order from the UNSC’s Presidency would be sufficient. The Committee is empowered to designate entities (natural and juridical persons) that are found involved in Iran’s nuclear or ballistic programs, and to oversee practical implementation of sanctions, including arms embargoes, asset freezes, and travel bans. It monitors compliance and handles exemption requests. The Committee typically takes decisions by consensus, either in formal meetings or through a written no-objection procedure.
The Panel of Experts consists of up to 8 members. They are appointed by the UN Secretary-General in consultation with the Committee. Experts typically have backgrounds in arms control, nuclear technology, export controls, finance, and maritime transport and insurance. They support the work of the Committee.
The list of UNSC resolutions imposing sanctions on Iran that are revived by operation the snapback includes the following:
- Resolution 1696 (2006) – Demanded Iran suspend uranium enrichment and comply with IAEA obligations.
- Resolution 1737 (2006) – Imposed the first round of sanctions, including asset freezes and export bans on nuclear-related materials.
- Resolution 1747 (2007) – Expanded sanctions to include arms embargoes and additional asset freezes.
- Resolution 1803 (2008) – Broadened travel bans and called for vigilance over Iranian banks and shipping.
- Resolution 1835 (2008) – Reaffirmed previous resolutions without adding new sanctions, reinforcing international pressure.
- Resolution 1929 (2010) – Significantly tightened sanctions, including restrictions on ballistic missile activity and military cooperation.
As one may observe, the reimposed UN sanctions on Iran significantly impact a range of economic sectors. Maritime transport and aviation are constrained by restrictions on the movement of sanctioned goods and denial of logistical support. The insurance industry faces prohibitions on coverage for transactions linked to Iran’s nuclear and military programs. Banking and finance are affected through asset freezes, limitations on international transfers, and enhanced scrutiny of Iranian institutions. Additionally, investment and funding channels are blocked, particularly those supporting Iran’s nuclear, missile, and arms-related activities, while trade in dual-use goods and technology is tightly controlled.
In addition, the snapback reinstates, inter alia, a prohibition on Iran’s exports of certain drones. Although the JCPOA did not treat unmanned aerial vehicles as missiles, UNSCR 2231 includes transfer and export restrictions covering drones (as dual-use or arms-related technologies). As a result, once snapback is triggered, Iranian drone exports — including those manufactured or assembled in Venezuela under the Maduro regime — and their transfer to Russia for use in Ukraine or to NATO territory (e.g. Poland) would become prohibited ipso facto.
Past Challenges in the 1737 Sanctions Committee (Pre-JCPOA)
The 1737 Sanctions Committee faced persistent difficulties in carrying out its mandate before the JCPOA. Although formally empowered to designate individuals and entities involved in Iran’s nuclear and missile activities, its work was frequently hampered by political divisions within the Security Council, especially objections from Russia and China, which were reluctant to approve designations targeting Iranian state bodies or companies. These disagreements often delayed or blocked consensus decisions, since the committee operates by the no-objection rule, and they limited the scope and speed of listings despite clear evidence of proliferation-sensitive activity. As a result, the committee’s effectiveness was constrained by geopolitical considerations, with enforcement uneven and implementation subject to the strategic interests of major powers.
It is important to mention the scheduled summit between Trump and Xi Jinping to take place at the end of October or beginning of November. As both have diverging interests but share a common goal of preventing Iran’s nuclear proliferation, this could otherwise result in most dangerous regional proliferation. The dynamics and deliberations of the Sanctions Committee may also benefit from the excellent mediation work of Rafael Grossi, Director General of the International Atomic Energy Agency (IAEA), whose impartial oversight and dialogue efforts are widely regarded as reliable by all parties involved. It is possible that neither the UNSC nor the UN Secretary-General takes any substantial decision on the snapback until October 18, 2025, which is the JCPOA’s formal expiration date.
EU Reimposes Sanctions on Iran
On September 29, following a similar move by the UN, the EU Council agreed to reimpose a number of restrictive measures in relation to Iran’s nuclear proliferation activities that had been suspended with the entry into force of the JCPOA. These sanctions operate independently of the UN and will be very helpful to overcome possible unjustified delays in designations by the UNSC’s Sanctions Committee. These sanctions are extremely important since they cover imports from Iran and the transport of crude oil, natural gas, petrochemical and petroleum products, and related services.
None of the UN resolutions highlighted above explicitly prohibited Iran’s export of oil or petroleum. Resolution 1929 did call on states to “exercise vigilance” over dealings with Iran’s energy sector and barred investment in Iranian oil/gas projects, but it did not impose a full ban on Iranian oil exports. That came only later through unilateral measures by the U.S. and EU, not the Security Council. The Europeans made it clear that their reimposition of sanctions does not mean, in any way, the end of diplomatic negotiations with Iran.
Current U.S. Sanctions on Iran
The United States maintains a broad and multifaceted sanctions regime on Iran, encompassing both primary sanctions, which prohibit U.S. persons and entities from engaging in transactions with Iran, and secondary sanctions, which target non-U.S. persons or entities that conduct significant business with Iran in sectors such as oil, banking, shipping, and military goods. Secondary sanctions are particularly significant because they extend U.S. jurisdiction extraterritorially: foreign companies, financial institutions, or states that violate these prohibitions risk losing access to the U.S. financial system or facing other punitive measures. This extraterritorial reach has a powerful effect in constraining Iran’s international trade and investment, making secondary sanctions one of the most effective tools in U.S. foreign policy toward Tehran.
Conclusion
The reimposition of UN sanctions on Iran through the snapback mechanism, together with the autonomous sanctions imposed by the EU and the comprehensive U.S. primary and secondary sanctions already in force, creates a powerful and multifaceted pressure on Iran.
The combined effect significantly constrains Iran’s ability to engage in international trade, access financial markets, and develop its nuclear, missile, and arms-related programs. Maritime transport, aviation, banking, insurance, and energy sectors are all affected, limiting both imports and exports, including critical oil and gas revenues. This integrated sanctions framework not only reinforces the legal and diplomatic authority of the UN but also ensures that gaps or delays in enforcement are mitigated through complementary measures by regional and global actors, exerting maximum economic and strategic pressure on Tehran.
