Supporting Terrorism

Undoubtedly, 9/11 changed the United States' foreign policy and national security. In the years following 9/11, the Department of Justice and law enforcement instituted numerous counter-terrorism measures, citing national security from further terrorist activity.

The United States has been subject to numerous terrorist attacks throughout its history. This article discusses the law against providing material support to terrorists and defines domestic and international terrorism. Read on to learn more about these crimes and find legal representation if you are charged with a federal crime against the government.

What Is Terrorism?

Federal law defines terrorism in the U.S. Code, Title 18, Chapter 113B. It defines international terrorism (18 U.S.C. § 2331) as the following:

  • It involves violent acts or acts dangerous to human life that violate United States criminal laws or would violate criminal law if committed in the United States.
  • The act must appear to intend to 1) intimidate or coerce civilians; or 2) affect government policy through coercion or intimidation; or 3) influence the government's conduct by mass destruction, assassination, or kidnapping.
  • The act occurs outside the United States or transcends national boundaries in terms of how the act is accomplished.

Domestic terrorism has the same elements, except that the acts primarily occur within the United States territorial jurisdiction. The Secretary of State has the authority to designate terrorist organizations.

September 11, 2001

On September 11, 2001, the Islamist terrorist group al Qaeda hijacked four airplanes in the United States. They crashed two of them into the World Trade Center towers in New York City and one into the Pentagon in Virginia. Passengers on the fourth plane fought the hijackers, and the plane ultimately crashed in a field in Pennsylvania. Nearly 3,000 people died in the attack, known as 9/11. It was the deadliest attack on U.S. soil since the Japanese navy attacked Pearl Harbor in 1941.

Although both 9/11 and Pearl Harbor involved attacks on the United States, only 9/11 was a terrorist attack. The attack on Pearl Harbor was an attack on a military base as an act of war. On 9/11, however, extremists and international terrorists mainly targeted the civilian population. Both attacks led to the United States joining or starting a war against the attackers.

Osama Bin Laden claimed responsibility for 9/11. The United States, along with international cooperation, soon invaded Afghanistan. They believed the Taliban in Afghanistan was hiding Bin Laden. In 2003, the United States invaded Iraq. At the time, U.S. intelligence was concerned about the danger of Iraq's weapons of mass destruction. Years later, these agencies revealed their information about the alleged weapons of mass destruction was incorrect.

Terrorist attacks can shape a nation's future. Whether it's policy changes regarding the threat of future terrorist acts or declaring war due to anti-terrorism concerns, terrorism shapes world history. For more information about terrorism, consider browsing FindLaw's Terrorism and Terroristic Threats article.

Supporting Terrorism: What Does That Mean?

Some terrorists act alone, while others have help. The United States federal government punishes those who assist in facilitating terrorist attacks.

The government can criminally charge people for aiding and abetting terrorism in multiple ways. This is codified in 18 U.S.C. Section 2339. The types of support, as upheld by the U.S. Supreme Court, are described as follows:

These methods are explained in more detail below.

Harboring or Concealing Terrorists

The federal government may prosecute anyone who harbors or conceals a person they know, or has reasonable grounds to believe, is a terrorist or will commit a terrorist act. Specifically, the statute lists that assistance or knowledge regarding the following actions are punishable by fines and up to 10 years of imprisonment:

  • The destruction of aircraft or aircraft facilities
  • Offenses related to biological weapons
  • Offenses related to chemical weapons
  • Offenses related to nuclear materials
  • The arson or bombing of government property risking or causing injury or death
  • The destruction of an energy facility
  • Violence against maritime navigation
  • Offenses related to weapons of mass destruction
  • Terrorism that transcends national boundaries
  • The sabotage of nuclear facilities or fuel
  • Aircraft piracy

If someone assists a terrorist in the above criminal activities, the government can bring a criminal case against them. For example, suppose someone knows their roommate is going to plant an explosive device at an airport. If they conceal their knowledge, the government may prosecute them in federal court.

Providing Material Support or Resources to Terrorists

Law enforcement agencies may arrest someone who provides material support or resources to a terrorist or terrorist group. This includes, but is not limited to, providing property, money, lodging, training, or weapons to terrorists. Punishment may include fines and imprisonment of up to 15 years. If their material support leads to the death of a person, they may face life in prison.

For example, suppose someone provides a safe house to a person they suspect will attack a U.S. energy facility. The person destroys the facility in a terrorist attack, resulting in the death of a U.S. government employee. The person who provided the safe house could face a fine and up to a life sentence in prison for providing material support and aiding and abetting terrorism.

Providing Material Support to a Terrorist Organization

Similar to providing support to an individual terrorist, citizens cannot provide support to terrorist organizations. The suspect does not necessarily have to support such an organization successfully. Plotting or conspiring to provide support is punishable by a fine and up to 20 years imprisonment. They may face a life sentence if their support results in a person's death.

This section also applies to financial institutions that become aware that they control funds in which a terrorist organization has an interest. The financial institution must report this information to the Secretary of the Treasury as soon as they know it.

The attorney general oversees all terrorism investigations. If a federal agency, such as the Federal Bureau of Investigation (FBI), suspects that someone provided support to a terrorist organization, they will refer it to the attorney general.

Prohibition on Financing of Terrorism

The law prohibits anyone from financing terrorists and terrorist organizations. The law applies to anyone who provides money or similar instruments to terrorists. It applies to illegally obtained money from organized crime, for example, money laundering and drug trafficking. The government does not have to prove the money was actually used to commit terrorism.

Financing a terrorist or terrorist organization could result in imprisonment of up to 10 years or 20 years depending on the circumstances.

Prohibition on Receiving Military-Type Training From Terrorist Organizations

If a person receives military-type training from an organization they know is designated as a terrorist organization or has engaged in terrorism, they are subject to fines and jail time. Military-type training involves training in the following means or methods:

  • Those causing death or serious injury
  • Those causing property damage or destruction
  • Those disrupting critical infrastructure services
  • Training in the use, storage, production, or assembly of explosives, firearms, or any other type of weapon, including weapons of mass destruction

If convicted, the person faces a fine and up to 10 years of imprisonment.


The American Civil Liberties Union (ACLU) has criticized these laws for alleged vagueness in defining material support statutes. The ACLU argues that these laws lead to convictions without having to show that someone committed a specific act of terrorism.

Advocates maintain these laws are sufficiently clear. They also argue they are necessary to keep America safe. The laws remain valid as of 2023.

Accused of Supporting Terrorism? Get in Touch With a Lawyer

Terrorism is a hot-button word in the world today. If the government charges you with aiding or abetting a terrorist organization, you should contact a skilled criminal defense attorney near you.

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