Federal Anti-Terrorism Law

Federal anti-terrorism law — centered on 18 U.S.C. §§ 2331–2339D and the economic sanctions framework under 50 U.S.C. §§ 1701–1707 — creates criminal liability for providing "material support or resources" to designated foreign terrorist organizations, financing terrorist acts, and using weapons of mass destruction, with penalties ranging from 20 years to life imprisonment (or death if the act results in a fatality). The material support statute (18 U.S.C. § 2339B) is the most heavily used tool: it broadly prohibits any "service, training, expert advice or assistance, personnel, or transportation" provided to an FTO — a definition the Supreme Court in Holder v. Humanitarian Law Project (2010) held extends even to speech coordinated with a designated organization. Designation as a Foreign Terrorist Organization (FTO) by the Secretary of State triggers both criminal prohibitions and automatic asset freezes. The International Emergency Economic Powers Act (IEEPA) gives the President sweeping authority to block financial transactions with designated countries, individuals, and entities — enforced by the Treasury's Office of Foreign Assets Control (OFAC), which maintains the Specially Designated Nationals (SDN) list. Since September 11, 2001, the U.S. anti-terrorism legal framework has expanded dramatically: the PATRIOT Act (2001), the Intelligence Reform and Terrorism Prevention Act (2004), and successive FISA amendments have layered surveillance, financing, and criminal authorities that define the operational landscape for financial institutions, nonprofits, and any organization with international connections.

Current Law (2026)

Legal Authority

• 18 U.S.C. § 2331 — Definitions (international terrorism: violent acts dangerous to human life that violate federal or state criminal law, intended to intimidate or coerce a civilian population or influence government policy; domestic terrorism: same, occurring primarily within U.S. territorial jurisdiction)
• 18 U.S.C. § 2332a — Use of weapons of mass destruction (WMD — chemical, biological, radiological, nuclear; against U.S. nationals or on U.S. property; penalty: death or imprisonment up to life)
• 18 U.S.C. § 2339A — Providing material support to terrorists (knowingly providing material support — money, lodging, training, weapons, personnel, transportation, expert advice — knowing it will be used in commission of specified federal terrorism offenses)
• 18 U.S.C. § 2339B — Providing material support to foreign terrorist organizations (knowingly providing material support or resources to a designated FTO; strict liability as to the organization's designation; up to 20 years; life if death results)
• 18 U.S.C. § 2339C — Prohibitions against financing of terrorism (providing or collecting funds with intent or knowledge they will be used for terrorist acts)
• 50 U.S.C. § 1701-1707 — International Emergency Economic Powers Act (IEEPA) (President may declare national emergency and impose sanctions — freeze assets, block transactions, prohibit trade — with respect to foreign threats; basis for terrorism-related executive orders and OFAC sanctions programs)
• 8 U.S.C. § 1189 — Foreign terrorist organization designation (Secretary of State may designate foreign organizations that engage in terrorist activity threatening U.S. nationals or national security; designation triggers material support criminal liability and immigration bars)
• 6 U.S.C. § 591 — Countering Weapons of Mass Destruction Office (DHS Assistant Secretary coordinates detection, prevention, and response to chemical, biological, radiological, and nuclear threats across the department and with interagency partners)
• 6 U.S.C. § 104-106 — National Biodefense Strategy (DHS, DOD, HHS, and USDA jointly develop and update national biodefense strategy biennially; OMB coordinates cross-agency biodefense budget analysis; implementation plan updated after each review)
• 6 U.S.C. § 422 — Procurements for defense against terrorism or CBRN attack (agencies may use streamlined procurement procedures for goods and services specifically for defending against or recovering from terrorism or CBRN attacks)

How It Works

Federal anti-terrorism law provides the legal framework for preventing, prosecuting, and punishing terrorist acts and the networks that support them. It combines criminal law (prosecuting individuals who commit or support terrorism), financial tools (freezing assets and blocking transactions), immigration bars (excluding terrorists and their supporters), and intelligence authorities.

The material support statutes — 18 U.S.C. §§ 2339A and 2339B — are the most commonly used federal anti-terrorism charges. Section 2339B makes it a federal crime to knowingly provide "material support or resources" to a designated foreign terrorist organization, regardless of whether the support was intended for violent activities. "Material support" is defined broadly: money, property, lodging, training, expert advice or assistance, personnel (including oneself), weapons, and transportation. The Supreme Court upheld the statute's breadth in Holder v. Humanitarian Law Project (2010), ruling that even training an FTO in peaceful conflict resolution constitutes material support because it frees up other resources for violence. Federal law also attacks terrorism through financial chokepoints: Treasury's Office of Foreign Assets Control (OFAC) administers sanctions programs that freeze U.S.-based assets of designated terrorists and prohibit transactions with them; banks must screen customers against OFAC's Specially Designated Nationals (SDN) list and report suspicious transactions under the Bank Secrecy Act and AML framework.

Foreign Terrorist Organization designation — made by the Secretary of State when an organization is foreign, engages in or has the capability and intent to engage in terrorist activity, and threatens U.S. nationals or national security — triggers automatic legal consequences: providing material support becomes a federal crime, U.S.-based assets are frozen, and members and supporters become inadmissible to the United States. Organizations may challenge their designation through a statutory review process in the D.C. Circuit. Domestic terrorism, by contrast, is defined in federal law (18 U.S.C. § 2331) but carries no specific federal domestic terrorism charge — domestic terrorist acts are prosecuted under other applicable federal statutes (hate crimes, weapons offenses, arson, murder) or state criminal law. Proposals to create a specific domestic terrorism charge have been repeatedly debated but not enacted, primarily because of concerns about overbreadth and the civil liberties implications of applying a terrorism label to protected political activity.

How It Affects You

If you work at a bank, credit union, money services business, or other financial institution: OFAC compliance and BSA/AML obligations are not optional — they're mandatory federal requirements with severe penalties. Your institution must screen customers and transactions against the Specially Designated Nationals (SDN) list maintained by OFAC (available at ofac.treas.gov), which includes ~1,500+ individuals, entities, and groups designated as terrorist-related. A match — even a "false positive" — requires a transaction hold and, if confirmed, a blocked assets report to OFAC. Civil penalties for OFAC violations can reach the greater of $250,000 or twice the transaction value per violation; criminal penalties for willful violations include up to 20 years imprisonment under IEEPA. If your institution serves customers with connections to sanctioned countries or persons, an OFAC compliance program (risk assessment, screening protocols, due diligence procedures, training, and auditing) is both legally required and your primary defense against enforcement action. Suspicious Activity Reports (SARs) filed with FinCEN are the parallel obligation for transactions that may involve terrorism financing — unusual international wire patterns, structuring, or transactions with FTO-connected individuals all trigger reporting obligations under the Bank Secrecy Act.

If you run a nonprofit, NGO, or humanitarian organization operating in conflict zones: The material support statutes create genuine legal risk for organizations that work in areas where designated Foreign Terrorist Organizations (FTOs) or Specially Designated Global Terrorists (SDGTs) are present. The Supreme Court held in Holder v. Humanitarian Law Project (2010) that even providing training in peaceful conflict resolution to an FTO constitutes material support — because it frees the organization's other resources for violence. In practice, this means: paying "taxes" or fees to an FTO-controlled authority in a conflict zone, coordinating logistics through FTO-held territory, or training FTO members in any skill (including peaceful advocacy) could theoretically expose your organization to prosecution. The practical safeguards: (1) OFAC general licenses for humanitarian activities in some sanctioned territories provide safe harbors — verify whether a license covers your specific operations; (2) specific licenses from OFAC can be obtained for activities not covered by general licenses; (3) document your due diligence on all payees and counterparties. Organizations like the U.S. Department of the Treasury's OFAC and the DOJ National Security Division provide guidance, but operational decisions in high-risk areas should be reviewed by legal counsel with national security expertise.

If you're an individual who has traveled to, donated to, or communicated with foreign organizations that may be designated: Section 2339B's strict liability for the organization's designation status is the trap for the unwary. You don't need to know the organization is designated — if it is an FTO and you knowingly provided material support (including money, lodging, transportation, personnel, or expert advice), you may have committed a federal crime. In practice, DOJ prosecutes cases where there's evidence of knowing support for violence, not ordinary charitable giving. But the statute's breadth has been used expansively. High-risk scenarios: wiring money to organizations in sanctioned regions without verifying their OFAC status; traveling to a conflict zone and paying fees to local authorities; sharing professional expertise with organizations operating in areas with active FTO presence. If you have any uncertainty about an organization's status, check the FTO list (State Department at state.gov/foreign-terrorist-organizations) and the SDN list (OFAC at ofac.treas.gov) before providing support. The civil liberties concern around material support law is real — the ACLU and Humanitarian Law Project have argued it unconstitutionally restricts First Amendment-protected speech and association — but courts have largely upheld the statute's reach.

If you're an attorney, compliance officer, or policy professional who works with national security law: The terrorism designation system has both administrative and judicial review mechanisms — but they're limited. Foreign Terrorist Organization designations by the Secretary of State are published in the Federal Register and can be challenged in the D.C. Circuit Court of Appeals (within 30 days of designation) or through administrative revocation petitions to the Secretary of State. OFAC SDN designations can be challenged through OFAC's administrative reconsideration process and, if denied, through federal district court under the APA — though courts give broad deference to executive national security determinations. For compliance work: the OFAC Consolidated Sanctions List is the authoritative source (accessible through ofac.treas.gov), is updated in real time, and is the list your institution is legally obligated to screen against. For material support analysis, the key question under § 2339B is whether the foreign organization is designated and whether your client's activities meet the definition of "material support or resources" — the statutory definition (18 U.S.C. § 2339A(b)) is the operative text. The DOJ National Security Division's Guidance for Humanitarian Organizations (available at justice.gov) provides practical compliance frameworks for nonprofit contexts.

State Variations

• Some states have enacted their own anti-terrorism statutes supplementing federal law
• State criminal law is used to prosecute domestic terrorism acts when federal charges are not applicable or not pursued
• State laws on money transmission and financial regulation may intersect with federal terrorism financing rules

Implementing Regulations

• 28 CFR Part 501 — Bureau of Prisons Scope of Rules — includes the foundational authority for the most restrictive measures BOP can impose on federal inmates. Key provisions:

  • § 501.1 — Emergency suspension: the BOP Director may suspend operation of any rules in 28 CFR Chapter V (the BOP regulatory chapter) as necessary to handle an institutional emergency — giving the Director broad discretion to override standard inmate rights during a lockdown, riot, or crisis period; the Warden has similar authority for local institutional emergencies; the suspension is supposed to be temporary (the rule specifies that normal procedures resume when the emergency ends)
  • § 501.2 — National security cases: upon direction of the Attorney General, the BOP Director may authorize a Warden to implement Special Administrative Measures (SAMs) — when the head of a federal intelligence agency certifies in writing that ordinary inmate communication would pose a substantial risk of disclosure of classified information that could damage national security; SAMs under § 501.2 restrict the inmate's communications with media, attorneys, and other inmates; the Attorney General authorization is the formal legal basis for the most restrictive conditions imposed on high-profile national security inmates
  • § 501.3 — Prevention of acts of violence and terrorism: upon direction of the Attorney General, the BOP Director may authorize SAMs for inmates whose communications could result in death or serious bodily injury; the threat must be to persons (domestic or foreign, in or outside the U.S.) and the restriction must be reasonably necessary to prevent it; the Attorney General must make a written finding; procedures may include: housing in a special management unit, strict limits on mail, monitoring of all phone calls and correspondence (including legal mail if a privilege team is established), restrictions on who the inmate may communicate with

  The § 501.3 SAMs authority is the legal basis for the most extreme solitary-adjacent conditions in federal prisons — used for inmates like Zacarias Moussaoui, Dzhokhar Tsarnaev, and certain cartel leaders whose communications could coordinate outside violence. SAMs can prohibit contact with specific family members, require all attorney communications to be monitored, and bar media access entirely. Courts have upheld SAMs under § 501.3 as long as the Attorney General's finding is not arbitrary, though First Amendment challenges regarding attorney-client communication monitoring remain active. SAMs are reviewed annually and can be renewed if the underlying threat assessment persists.

• 28 CFR Part 16 — DOJ Privacy Act (§ 16.105 — exemption of Foreign Terrorist Tracking Task Force systems)

• 31 CFR Parts 594–598 — OFAC terrorist sanctions programs (Specially Designated Nationals, blocked persons, terrorist financing prohibitions)

• 6 CFR Part 27 — Chemical Facility Anti-Terrorism Standards (CFATS)

Pending Legislation

• HR 7512 — Extend DHS Countering WMD Office authorization through Feb 2027. Status: Introduced.
• HR 5247 (Rep. Self, R-TX) — New Under Secretary for International Security, bureaus for counterterrorism. Status: In committee.
• HR 5148 (Rep. Lawler, R-NY) — Broaden State Dept counterterrorism aid to foreign intel/military units. Status: Introduced.
• HR 5352 (Rep. Van Orden, R-WI) — Bar federal funding to orgs employing those who condone political violence. Status: Introduced.

H.R. 6230 — Tehran Incitement to Violence Act would impose sanctions on Iranian officials who incite violence against individuals in the United States, targeting regime-directed threats against dissidents and others on U.S. soil. The bill was ordered reported by the House Committee on Foreign Affairs on December 3, 2025. The Congressional Budget Office published a cost estimate on February 3, 2026. H.R. 6230, Tehran Incitement to Violence Act

H.R. 4335 — Abraham Accords Defense Against Terror Act would expand U.S. counterterrorism cooperation with Abraham Accords partner nations. The bill was ordered reported by the House Committee on Foreign Affairs on July 22, 2025. The Congressional Budget Office published a cost estimate on February 28, 2026. H.R. 4335, Abraham Accords Defense Against Terror Act

Recent Developments

• Domestic terrorism — including ideologically motivated mass shootings and attacks on government facilities — has become a priority focus for DOJ and FBI
• Debates over a specific federal domestic terrorism statute continue without resolution
• OFAC sanctions programs targeting terrorism have expanded, particularly in connection with state sponsors of terrorism
• Cryptocurrency and decentralized finance have created new challenges for terrorism financing detection and enforcement
• Material support prosecutions continue to be the primary federal tool against individuals who attempt to join or support foreign terrorist organizations. The federal death penalty applies to terrorism offenses resulting in death

On January 13, 2026, the Treasury and State Departments jointly designated Muslim Brotherhood branches as terrorist organizations, adding them to both the Foreign Terrorist Organization list and the OFAC Specially Designated Nationals list. The action represents a significant expansion of the U.S. terrorism designation framework to include a transnational Islamist organization with affiliates operating across numerous countries. These designations trigger automatic asset freezes and material support criminal liability under 18 U.S.C. § 2339B for any knowing provision of support to the designated branches. Treasury/State Departments Designate Muslim Brotherhood Branches as Terrorist Organizations

On January 16, 2026, OFAC published a counter-terrorism designation update adding new individuals and entities to the Specially Designated Nationals list under its terrorism-related sanctions programs. This action reflects continued use of the designation framework to expand the SDN list beyond the January 13, 2026 Muslim Brotherhood action already noted in the article. The update is part of OFAC's Office of Terrorism and Financial Intelligence's ongoing enforcement activity. Counter Terrorism Designations and Designation Update

On January 16, 2026, the Treasury Department announced new OFAC designations targeting Houthi smuggling and illicit revenue generation networks, increasing financial pressure on the group's financing operations. The action adds individuals and entities connected to Houthi revenue streams to the Specially Designated Nationals list, triggering asset freezes and transaction prohibitions under the IEEPA-based sanctions framework. This represents a continued expansion of OFAC's counter-terrorism enforcement activity against the Houthis, a designated Specially Designated Global Terrorist organization, beyond prior designation actions. Treasury Increases Pressure on Houthi Smuggling and Illicit Revenue Generation Networks

On January 21, 2026, OFAC published a counter-terrorism designations and designations removals update, adding new individuals and entities to — and removing others from — the Specially Designated Nationals list under its terrorism-related sanctions programs. The action reflects continued enforcement activity by Treasury's Office of Terrorism and Financial Intelligence and is distinct from the January 13 Muslim Brotherhood designations and the January 16 Houthi network and general counter-terrorism updates already noted. Removals from the SDN list are a routine but legally significant component of OFAC's designation framework, as they lift asset freezes and transaction prohibitions for affected parties. Counter Terrorism Designations and Designations Removals

On January 21, 2026, the Treasury Department announced OFAC designations targeting a covert Hamas support network, adding individuals and entities connected to Hamas's financing and operational infrastructure to the Specially Designated Nationals list. The action is distinct from the January 21 counter-terrorism designations update already noted and represents a focused enforcement action against Hamas — a designated Foreign Terrorist Organization — under the IEEPA-based sanctions framework. Asset freezes and transaction prohibitions attach automatically to the newly designated parties, and any knowing provision of material support to them triggers criminal liability under 18 U.S.C. § 2339B. Treasury Exposes and Disrupts Hamas's Covert Support Network

On January 23, 2026, the Treasury Department announced OFAC designations escalating financial pressure on the Iranian regime in response to the killing of peaceful protesters, adding individuals and entities connected to the Iranian government's suppression of protests to the Specially Designated Nationals list. The action is distinct from prior 2026 designation actions targeting the Muslim Brotherhood, Houthi networks, and Hamas, and reflects continued use of the IEEPA-based sanctions framework against Iran beyond its role as a designated state sponsor of terrorism. Asset freezes and transaction prohibitions attach automatically to the newly designated parties. Treasury Escalates Pressure on Iranian Regime for Killing Peaceful Protestors

On January 30, 2026, OFAC published a combined update covering Iran-related designations, counter-terrorism designations, a non-proliferation designation update, and a designation removal, adding new individuals and entities to — and removing at least one from — the Specially Designated Nationals list across multiple sanctions programs. The action is distinct from the January 21 and January 23 designation actions already noted and reflects continued enforcement activity by Treasury's Office of Terrorism and Financial Intelligence across terrorism, Iran, and non-proliferation authorities simultaneously. Removals from the SDN list lift asset freezes and transaction prohibitions for affected parties, while new designations trigger automatic asset freezes and, where terrorism-related, criminal liability under 18 U.S.C. § 2339B for any knowing provision of material support. Iran-related Designations; Counter Terrorism Designations; Non-Proliferation Designation Update and Designation Removal

On January 30, 2026, the Treasury Department announced OFAC designations targeting Iranian regime officials for violent repression and corruption, adding individuals to the Specially Designated Nationals list under the IEEPA-based sanctions framework. This action is distinct from the January 30 combined Iran/counter-terrorism/non-proliferation update already noted and represents a focused enforcement action against Iranian officials specifically for repression and corruption rather than terrorism financing. Asset freezes and transaction prohibitions attach automatically to the newly designated parties. Treasury Sanctions Iranian Regime Officials for Violent Repression and Corruption

On February 10, 2026, the Treasury Department announced OFAC designations targeting operatives generating revenue for Hizballah and exploiting Lebanon's cash economy, adding individuals and entities connected to Hizballah's financing networks to the Specially Designated Nationals list under the IEEPA-based sanctions framework. The action is distinct from prior 2026 designation actions targeting the Muslim Brotherhood, Houthi networks, Hamas, and Iranian officials, and represents a focused enforcement action against Hizballah — a designated Foreign Terrorist Organization — beyond earlier designation rounds. Asset freezes and transaction prohibitions attach automatically to the newly designated parties, and any knowing provision of material support to them triggers criminal liability under 18 U.S.C. § 2339B. Treasury Sanctions Operatives Generating Revenue for Hizballah and Exploiting Lebanon's Cash Economy

On February 25, 2026, the Treasury Department announced OFAC designations targeting Iran's shadow fleet and networks supplying ballistic missile and advanced conventional weapons (ACW) programs, adding individuals and entities connected to Iranian weapons procurement and revenue generation to the Specially Designated Nationals list under the IEEPA-based sanctions framework. The action is distinct from prior 2026 designation actions targeting Houthi networks, Hamas, Hizballah, and Iranian officials for repression, and represents a focused enforcement action against Iran's weapons supply infrastructure beyond earlier rounds. Asset freezes and transaction prohibitions attach automatically to the newly designated parties. Treasury Targets Iran's Shadow Fleet, Networks Supplying Ballistic Missile and ACW Programs

On February 26, 2026, the Treasury Department announced OFAC designations targeting Nicaraguan officials enabling the Murillo-Ortega dictatorship's repression, adding individuals to the Specially Designated Nationals list under the IEEPA-based sanctions framework. The action is distinct from prior 2026 designation actions targeting Houthi networks, Hamas, Hizballah, Iranian officials, and Iran's weapons supply infrastructure, and reflects continued use of OFAC's sanctions authorities against foreign government officials for human rights abuses and political repression. Asset freezes and transaction prohibitions attach automatically to the newly designated parties. Treasury Sanctions Nicaraguan Officials Enabling the Murillo-Ortega Dictatorship's Repression

On March 2, 2026, OFAC published a Democratic Republic of the Congo-related designations action, adding individuals and entities connected to the DRC conflict to the Specially Designated Nationals list, accompanied by the issuance of an associated general license. The action is distinct from prior 2026 designation actions targeting Houthi networks, Hamas, Hizballah, Iranian officials, Iran's weapons supply infrastructure, and Nicaraguan officials, and reflects continued use of OFAC's sanctions authorities — administered by Treasury's Office of Terrorism and Financial Intelligence — beyond terrorism-specific programs. Asset freezes and transaction prohibitions attach automatically to the newly designated parties, while the associated general license carves out authorized transactions for specified activities. Democratic Republic of the Congo-related Designations; Issuance of Associated General License

On February 27, 2026, OFAC published a combined update covering Russia-related designation removals and a Lebanon designation removal, lifting asset freezes and transaction prohibitions for the affected parties across multiple sanctions programs. Removals from the SDN list are a legally significant component of OFAC's designation framework, as they terminate automatic asset freezes and, where terrorism-related designations are involved, extinguish the basis for criminal material support liability under 18 U.S.C. § 2339B for newly removed parties. The action is distinct from prior 2026 designation actions targeting Houthi networks, Hamas, Hizballah, Iranian officials, and other parties already noted. Russia-related Designations Removals; Lebanon Designation Removal

On February 25, 2026, OFAC published a combined update covering Iran-related designations and non-proliferation designations, adding new individuals and entities to the Specially Designated Nationals list across multiple sanctions programs administered by Treasury's Office of Terrorism and Financial Intelligence. This action is distinct from the February 25 action targeting Iran's shadow fleet and ballistic missile supply networks already noted, and reflects simultaneous use of both terrorism and non-proliferation authorities in a single enforcement update. Asset freezes and transaction prohibitions attach automatically to the newly designated parties, and where terrorism-related designations are involved, criminal liability under 18 U.S.C. § 2339B attaches to any knowing provision of material support. Iran-related Designations; Non-Proliferation Designations