Research Guide: Law of International Armed Conflict

First Published 31 Oct 2023. Revised November 8, November 20, 2023 & January 21, 2024.

High emotions generated by the Israel-Hamas conflict make this a time of wild claims and counterclaims. Few subjects are timelier and more critical than the Law of Armed Conflict, (LOAC), frequently referred to as the Law of War, (LOW). The concept is sometimes referred to by a better name, International Humanitarian Law (IHL). Researching LOAC/LOW/IHL can challenge U.S. researchers and lawyers. There are no codified statutes or well-organized case law of the types familiar to most U.S. researchers.

There are precedents, but rather than a system of U.S.-style case law, neatly organized by jurisdiction, there is a set of often vague or disputed concepts known as “customary international law.” One expert defines it as “rules of law derived from the consistent conduct of States acting out of the belief that the law required them to act that way.”

Difficulties in interpreting and applying this definition have led to the creation of multiple treaties. These treaties generally bind only nations that have ratified them.

This resource guide is part of the LLRX Israel-Hamas War Project. Our goal is to make it easier for policymakers, diplomats, analysts, reporters, scholars, and the public at large to find objective, accurate, and actionable information concerning the Israel-Hamas conflict. We welcome suggestions for adding additional research links or otherwise improving this guide.

On January 19, 2024, I added these critical facts that serve as the foundation of this guide – “…the scale of the tunnels in Gaza, the Israel-Hamas war is the first war in which a combatant has made its vast underground network a defining centerpiece of its overall political-military strategy.” The article, by John Spencer, was published on the Modern War Institute at West Point site, January 18, 2024. I have snipped a key portion but urge you to read the article in its entirety.

Before the Israel-Hamas war, both the presence of Hamas tunnel networks and their growth over the years were very well known. The network was referred to as Gaza’s “Metro” or “lower Gaza.” The Israel Defense Forces (IDF) and scholars estimated before the war that there were three hundred miles of tunnels ranging from fifteen feet to over two hundred feet below the surface. The estimates were wrong.

After three months of close combat and discovering over 1,500 tunnel shafts and underground passages, the IDF has learned enough to require the estimates to be revised. Israeli forces have unearthed massive invasion tunnels two and a half miles long, underground manufacturing plants, luxury tunnels with painted walls, tile floors, ceiling fans, and air conditioning, and a complex, layered, labyrinth underneath all areas of Gaza. The new estimates say the network may include between 350 and 450 miles of tunnels, with close to 5,700 separate shafts descending into hell.

New estimates also indicate the construction of this subterranean network could have cost Hamas as much as a billion dollars. The group has poured resources over fifteen years not just into constructing tunnel passages, but for blast doors, workshops, sleeping quarters, toilets, kitchens, and all the ventilation, electricity, and phone lines to support what amount to underground cities. As much as 6,000 tons of concrete and 1,800 tons of metals have been used in this subterranean construction.

The sheer size of Hamas’s underground networks may, once fully discovered, be beyond anything a modern military has ever faced. One of the last conflicts that involved a large amount of tunnel complexes was the Vietnam War. American forces and others faced some tunnel complexes that ranged up to forty miles in length and one of the most concentrated places of tunnels, near Saigon at Cu Chi, contained 130 miles of passageways.

The second set of facts come via Newsweek, and this lead article published on January 17, 2024 – Hamas, Inc.: The Property Empire That Funded Militant Attack on Israel – The financial muscle behind the militant group.

By examining business records and cross-referencing them with the sanctions lists, Newsweek’s investigation shows how Hamas is using some of its key personnel to set up such companies around the Middle East and elsewhere to run its financial empire—often in places where, one expert said, it may find tacit approval for such operations. They include businesses in the United Arab Emirates, Turkey, Algeria, Saudi Arabia and Sudan, and may even reveal how the group is expanding into Western Europe. It also illustrates that while the unprecedented aerial and ground assault on Gaza, which Israel says is necessary to ensure Hamas’ destruction, may paralyze the militant group there, it seems unlikely to stop the flow of funds from abroad…”In addition to the funds Hamas receives from Iran, its global portfolio of investments generates vast sums of revenue through its assets, estimated to be worth hundreds of millions of dollars, with companies operating in Sudan, Algeria, Türkiye, the United Arab Emirates, and other countries,” the U.S. Treasury said in a statement when it updated its Hamas sanctions list on October 18, 2023. “The companies in Hamas’ portfolio have operated under the guise of legitimate businesses and their representatives have attempted to conceal Hamas’ control over their assets. “This investment network is directed by the highest levels of Hamas leadership and has allowed Hamas senior officials to live in luxury while ordinary Palestinians in Gaza struggle in harsh living and economic conditions.”…The Israeli government also says that construction companies are a vital part of the Hamas finance model and has mirrored the U.S. sanctions list. In an online statement on October 29, the Israeli embassy in the U.S. said that Moussa Abu Marzouk, deputy chair of the Hamas Political Bureau, was worth $3 billion, while senior leaders Khaled Mashal and Ismail Haniyeh were each worth about $4 billion.The reason that Hamas has turned to property is clear, experts say. Stephen Reimer, a senior research fellow at the U.K.’s Royal United Services Institute, told Newsweek that “building and then selling real estate is a handy way for Hamas to obfuscate its funds.”…

Scope Limitations

This resource guide attempts to avoid two areas:

  • Factual findings or conclusions. It is too early for such assessments. For example, multiple sources seem to take it as a given that the Israeli bombing of Gaza constitutes a war crime. This conclusion is premature. There is yet no little or no reliable evidence on questions like the selection of targets, disproportionate use of force, and so on.
  • Analysis of Crimes against humanity, including genocide. These concepts differ from LOAC. They were first prosecuted as separate crimes at Nuremberg. Some reputable scholars have concluded that Israel’s historical treatment of the Palestinians has been immoral and abhorrent. Other reputable scholars have come to different conclusions. However, we do not attempt to resolve the inconsistency in this guide. Even if the first view were to be accepted, it is also true that immoral and abhorrent conduct is not necessarily a crime against humanity as legally defined.

While there is no unanimity on this issue, the sense is that most reputable and objective scholars believe that while Israel’s conduct has not always been above reproach, there is no reasonable basis to assert that Israel has committed crimes against humanity of the types prosecuted at Nuremberg or being committed by the terrorist component of Hamas today.

On the other hand, Hamas openly states that their goal is genocide. This is not an admission. It is a boast.

International Documents

United Nations

International Committee of the Red Cross – The ICRC is a rich source of high-quality analysis and links to primary sources. The casebook section links to court decisions and white papers from government sources, including some otherwise-hard-to-find documents from the U.S. Department of Justice:

The Council on Foreign Relations

U.S. State Department

U.S. Department of Defense

U.S. Army

These resources are superior to the Department of Defense Law of War Manual in some ways:

Library of Congress (LOC)

LOC’s Military Collection has three components:

Congressional Research Service (CRS)

CRS is a nonpartisan organization created to provide objective analysis to congressional committees and Members of Congress. Following are recent relevant publications. These can be updated relatively frequently so it’s best to check for a more recent version.

Selected News Articles and Updates Providing Background/Context

Just Security – Expert Guidance: Law of Armed Conflict in the Israel-Hamas War – This reference has several strong points, including distinguishing between areas where the law is well-settled and clear and where it is less so.

The Conversation – How the ‘Laws of War’ Apply to the Conflict Between Israel and Hamas

Slate – Why There’s No End in Sight For the Israel-Hamas War

New York Times What I Believe as a Historian of Genocide

The Atlantic –  A Knife Fight in a Phone Booth

CNN  Updates

Times of IsraelUpdates

Deutsche Welle What Constitutes A War Crime?

Global Investigative Journalism NetworkWhat Is Legal In War?

U.S. News & World Report – Key Historical Events in the Conflict Between Israelis and Palestinians 


Academic Sources

Duke University Law School

Michigan Journal of International Law

Brandeis University

Yale Law School What is a War Crime? (March 30, 2019).  Full text.

George Washington UniversityThe Ironic History of Palestine.

Closing Thought: A Concise Summary of Some Key LOAC Concepts

No doubt some readers will be daunted by the prospect of digesting the sources referenced above and prefer a Cliff Notes approach. Here is the U.S. Army’s admirably concise summary of the fundamental rules. This excerpt from The Commander’s HandbookAR 350-1, Table F-2 condenses the mountain of legalese into the minimum knowledge required for all Army members:

The Soldier’s Rules

  • Soldiers fight only enemy combatants.
  • Soldiers do not harm enemies who surrender. They disarm them and turn them over to their superior.
  • Soldiers do not kill or torture any personnel in their custody.
  • Soldiers collect and care for the wounded, whether friend or foe.
  • Soldiers do not attack medical personnel, facilities, or equipment.
  • Soldiers destroy no more than the mission requires.
  • Soldiers treat civilians humanely.
  • Soldiers do not steal. Soldiers respect private property and possessions.
  • Soldiers should do their best to prevent violations of the law of war.
  • Soldiers report all violations of the law of war to their superiors.

Author Notes

Mr. Lawson’s experience as a military and civil service lawyer includes assignments to the Pentagon, the U.S. Army, and the Agency for International Development. He holds a J.D. from the University of Kentucky and is a Commandant’s List graduate of The Judge Advocate Legal Center and School Basic Course. He holds an LL.M. from the same school. His active-duty military responsibilities included teaching the law of war to soldiers. 

Ms. Pacifici is a law librarian with over forty years of experience in the private, government and academic sectors. She is the Founder, Editor, Publisher of the award-winning monthly e-journal and the daily research blog, beSpacific.

Creative Commons License

Research Guide: Law of Armed Conflict© 2023 by Jerry Lawson and LLRX® is licensed under CC BY-NC-ND 4.0  Republishing With Appropriate Attribution Encouraged.

Posted in: Legal Research