Blocking vs. Restricting (SDN vs. Sectoral)

The distinction between blocking sanctions and sectoral sanctions is foundational to the operation of United States economic statecraft as administered by the Office of Foreign Assets Control (OFAC) within the Department of the Treasury. Blocking sanctions derive their authority principally from the International Emergency Economic Powers Act (IEEPA, 50 U.S.C. §§ 1701–1708) and, in wartime contexts, the Trading with the Enemy Act of 1917. When the President declares a national emergency under IEEPA, the Treasury Secretary may designate persons whose property and interests in property within U.S. jurisdiction are "blocked"—a term of art meaning frozen in place, untransferable, and effectively quarantined. Sectoral sanctions, by contrast, emerged as a calibrated alternative first deployed at scale in Executive Order 13662 of March 20, 2014, which authorized restrictions on identified sectors of the Russian Federation economy following the annexation of Crimea, and was implemented through the Sectoral Sanctions Identifications (SSI) List.

Blocking operates through inclusion on the Specially Designated Nationals and Blocked Persons List (the SDN List). Once a person is designated, every U.S. person—every U.S. citizen, permanent resident, entity organized under U.S. law including foreign branches, and any person physically present in the United States—must immediately freeze any property of the designated person in their possession or control and file a blocking report with OFAC within ten business days under 31 C.F.R. § 501.603. All transactions involving that property are prohibited absent a specific or general license. The blocking obligation extends through the 50 Percent Rule, articulated in OFAC guidance dated August 13, 2014, which automatically blocks any entity owned 50 percent or more, individually or in the aggregate, by one or more blocked persons, even if that subsidiary is not itself listed.

Sectoral sanctions function differently. Rather than freezing assets, they prohibit specified categories of transactions while permitting all others. The Russia program established four directives under E.O. 13662: Directive 1 restricted new equity and debt of specified tenor for financial institutions; Directive 2 restricted new debt for energy firms; Directive 3 restricted new debt for defense firms; Directive 4 restricted the provision of goods, services, and technology supporting Russian deepwater, Arctic offshore, and shale oil projects. A U.S. person may continue to hold legacy securities, maintain correspondent accounts, and conduct ordinary trade with SSI-listed entities—what is forbidden is the specific conduct enumerated in the applicable directive. The Countering America's Adversaries Through Sanctions Act (CAATSA) of 2017 subsequently shortened permitted debt tenors and codified portions of the regime.

Contemporary practice illustrates the divergence. When OFAC designated Sberbank and VTB Bank as SDNs following Russia's February 2022 invasion of Ukraine, the institutions' U.S.-situs assets were frozen and U.S. persons were required to wind down dealings under general licenses issued by Treasury's Russian Harmful Foreign Activities Sanctions program. Earlier, under the 2014 sectoral framework, those same banks had appeared on the SSI List, where U.S. counterparties could continue routine correspondent banking but could not extend new long-dated debt. The Iran program under E.O. 13599 and the Global Magnitsky program under E.O. 13818 of December 20, 2017, rely exclusively on blocking. The Venezuela program combines both modalities, with PdVSA blocked under E.O. 13850 in January 2019 while certain debt restrictions had operated previously under E.O. 13808.

Sectoral sanctions are frequently confused with secondary sanctions, but the concepts are distinct. Secondary sanctions—exemplified by the Iran Freedom and Counter-Proliferation Act and Section 231 of CAATSA—target non-U.S. persons for engaging with sanctioned parties, exposing them to potential SDN designation or loss of access to the U.S. financial system. Sectoral measures, by contrast, bind only U.S. persons and limit only the enumerated conduct. Likewise, sectoral sanctions differ from menu-based sanctions such as those under CAATSA Section 235, where the President selects from a statutory menu of penalties. The non-SDN Menu-Based Sanctions List (NS-MBS List) and the Non-SDN Chinese Military-Industrial Complex Companies List (NS-CMIC List) under E.O. 13959, as amended by E.O. 14032 of June 3, 2021, represent further refinements that restrict securities transactions without blocking property.

Controversies center on overcompliance and ambiguity. Banks frequently de-risk by treating SSI entities as if blocked, exiting relationships that remain legally permissible—a phenomenon OFAC has addressed in successive guidance. The 50 Percent Rule's application to sectoral entities was clarified in FAQ 398, which extends the rule to SSI status: an entity 50 percent owned by an SSI party is itself subject to the same directive restrictions. The 2022 Russia campaign blurred lines further by layering correspondent account prohibitions (Directive 2 under E.O. 14024), debt and equity restrictions (Directive 3), and outright blocking across overlapping populations, requiring compliance officers to map each counterparty against multiple authorities simultaneously.

For the practitioner, the operational consequence is dispositive. A blocking designation terminates the commercial relationship; a sectoral designation reshapes it. Trade finance teams, custodians, and sanctions screening vendors must distinguish between SDN hits—which trigger immediate freezes, rejected wires, and blocking reports—and SSI or non-SDN list hits, which require transaction-level analysis against the governing directive. Misclassification in either direction produces enforcement exposure: under-compliance invites civil penalties under 50 U.S.C. § 1705 of up to the greater of $356,579 (as adjusted) or twice the transaction value per violation, while over-compliance can constitute unlawful denial of services and damages diplomatic equities. Mastery of the blocking-versus-restricting axis is therefore the threshold competency for any sanctions desk.