More than 45 Palestinian civilians were killed on May 26 in a fire caused by an unprovoked Israeli airstrike at the Kuwait Peace Camp 1 in Rafah1. According to images reviewed by weapons experts, the bombs that Israel dropped were American bombs called GBU-39s2.

The purpose of the airstrike was purportedly to kill two Hamas leaders close to the encampment. In the process, Israel’s military believes that one or both GBU-39s inadvertently hit a fuel tank that was located approximately 100 feet from the Hamas targets, which induced a second explosion that then subsequently led to the encampment catching on fire3. It is also possible that the shrapnel from the GBU-39s ignited gas canisters or cooking stoves that were stored inside the refugees’ tents4. The encampment was in a neighborhood, Tal al-Sultan, that Israel had designated as a safe zone, ordered civilians to evacuate to using paper pamphlets, and knew was sheltering a high saturation of civilians at the time5. An official investigation as to the source of the blaze is still ongoing6.

The GBU-39 was designed at the Lawrence Livermore National Laboratory (LLNL) beginning in 2001 as part of a contract with the U.S. Air Force7. LLNL is a nuclear weapons lab located in Livermore, California and operated by a consortium of universities and private weapons companies8. Although its main purpose is to design nuclear weapons for the DOE’s National Nuclear Security Administration (NNSA) and 84.3% of its $2.36 billion federal budget is dedicated to nuclear weapons research9, it occasionally also develops conventional weapons technologies such as the GBU-39.

The GBU-39’s first appearance in an active war zone occurred in 2006 during the Iraq War10. It is manufactured by The Boeing Company and Woodward, Incorporated, at a facility in Fort Collins, Colorado11 and sold to Israel both directly via commercial sales and indirectly via Pentagon channels. Israel’s use of the GBU-39 in Gaza has been well-documented in several other airstrikes dating back to May 2023, all of which, like last month’s attack, resulted in a large number of civilian fatalities12.

The GBU-39 weighs 250 pounds and is often referred to as a small-diameter bomb because it is intended to create small but highly lethal explosions at discrete locations, thus minimizing the collateral damage to the surrounding areas. It is also referred to as a smart bomb because when it is dropped from the air it is encapsulated inside a GPS-guided missile that increases its geographic accuracy, unlike so-called dumb bombs, which are dropped from the air and land wherever the wind carries them13.

For these reasons, the U.S. military has consistently encouraged Israel to use the GBU-39 in lieu of dumb bombs when it is targeting Hamas terrorists in densely populated urban areas, arguing that the GBU-39 will result in fewer civilian casualties14. Section 1275 of the U.S.’ National Defense Authorization Act, passed in 2021, grants U.S. private companies the ability to sell precision-guided munitions such as GBU-39s to Israel without the Congressional approval that would otherwise be necessary for foreign weapons transfers15.

This Section 1275 exemption was a windfall for Boeing. From 2021-2023, Israel purchased at least 2,914 GBU-39 bombs from the U.S.16, 1,000 of which arrived in a singular Air Force shipment the week after the October 7 attacks17. On May 8, 2024, as world leaders urged the U.S. to use their diplomatic power to stop Israel’s impending ground invasion of Rafah, the Biden Administration decided to pause shipments of the heavier, large-diameter 2,000 pound and 500 pound U.S. bombs that it had originally been sending to Israel18. This further increased Israel’s reliance on the American small-diameter bombs in its arsenal, such as the GBU-39.

GBU-39s provide the IDF with the easy option of dropping a quote-unquote smaller bomb in civilian areas while keeping their soldiers at a safe distance. Without the GBU-39, Israel would likely be showing much more restraint, specifically in situations where it knows that the use of larger-diameter 2,000 pound bombs in cities or refugee camps would not be tolerated by the U.S. or its other allies. Sending ground soldiers or remote-controlled drones to kill Hamas operatives would come with a greater risk of violence against IDF soldiers or property, and thus, these less favorable options to Israel’s military officials19.

The GBU-39, in other words, causes less fatalities than larger-diameter bombs when detonated, but is being used in combat zones where bombs should never be detonated in the first place, according to international law20. Although certainly less destructive than 2,000 pound or 500 pound bombs, the 250 pound GBU-39 still spreads shrapnel up to 2,000 feet in every direction from the original site of its implosion21 As demonstrated over the past eight months, Israel’s Air Force either lacks the skill or the compassion to ensure that innocent civilians do not find themselves inside the debris field.

Instead of using their leverage to demand a change in Israeli bombing tactics, U.S. weapons companies have provided Israel with a near-infinite supply of GBU-39s and other alternative bombs, thus green-lighting the continued murder of thousands of innocent civilians under the guise of what Israel claims are targeted assassinations of Hamas terrorists, but which are actually far more indiscriminate than other means.

Those who build dangerous weapons, like the scientists at Lawrence Livermore National Laboratory, often do so under a false rationalization that the weapons will result in less collateral damage or fewer civilian deaths. Yet these scientists rarely have a voice in determining where or how the weapons will be used. And that is the precise reason they should never be built at all.


1. Al-Shalchi, Hadeel. Baba, Anas. “Israeli airstrike kills 45 Palestinians in an encampment for displaced people.” NPR. May 27, 2024.

2. Stein, Robin. Triebert, Christiaan. Willis, Haley. “Israel Used U.S.-Made Bombs in Strike That Killed Dozens in Rafah.” New York Times. May 27, 2024.

3.  Da Silva, Chantal. “Israeli tanks reach central Rafah; Outrage over deadly camp strike grows.” NBC. May 28, 2024.

4. Magdy, Samy. Shurafa, Wafaa. “Israeli strikes kill at least 37 Palestinians, most in tents, near Gaza’s Rafah as offensive expands.” ABC. May 28, 2024.

5. Schmunk, Rhianna. “Israel’s deadly attack on tent camp confirms ‘there is no safety’ in Gaza, survivors say.” CBC. May 27, 2024.

6. Da Silva, Chantal. Pinson, Shira. Chiwaya, Nigel. Mulligan, Matthew. Abbas, Mo. “Fire raging, blood everywhere: What we know about Israeli strike on a tent camp in Rafah.” NBC News, June 11, 2024.

7. “Advanced Conventional Weapons.” Lawrence Livermore National Laboratory. April 23, 2019.

8. Vartabedian, Ralph. “Consortium wins contract to run Livermore lab.” Los Angeles Times, May 9, 2007.

9. Kelley, Marylia. “Livermore Lab Budget: Everything for Nukes, Pennies for Cleanup.” TriValley CARES, May 25, 2023.

10. Wicke, Russell. “ACC declares small diameter bomb initially operational.” Air Force. October 5, 2006.

11. Binder, Alex. “Hundreds Rally Outside Colorado-Based Defense Contractor, Call for Divestment and Accountability.” Unicorn Riot. November 16, 2023.

12. “Amnesty International USA Submission to NSM-20.” Amnesty USA. April 29, 2024.

13. “GBU-39B Small Diameter Bomb Weapon System.” Air Force.

14.  Entous, Adam. Barnes, Julian E. Schmitt, Eric. “U.S. Officials Outline Steps to Israel to Reduce Civilian Casualties.” New York Times. November 4, 2023.

15. Abou-Elias, Janet. Mauldin, Lillian. Tolany, Ari. “How Israel Got an Endless Supply of U.S.-Made Smart Bombs.” In These Times. December 4, 2023.

16. Popescu, Teo. “Graphic: Boeing was top U.S. manufacturer of missiles and munitions delivered to Israel from 2021-2023.” KUOW. May 13, 2024.

17. Capaccio, Anthony. “Boeing Sped 1,000 Smart Bombs to Israel After Hamas Attacks.” Bloomberg. October 10, 2023.

18.Copp, Tara. “Why the U.S. paused the delivery of 2,000-pound bombs to Israel ahead of a possible assault on Rafah.” PBS. May 8, 2024.

19. Copp, Tara. Federman, Josef. “Israel could have used smaller weapons against Hamas to avoid deaths in Gaza tent fire, experts say.” Associated Press. May 30, 2024.

20. Farge, Emma. “‘Immense’ scale of Gaza killings amount to crime against humanity, UN inquiry says.” Reuters, June 12, 2024.

21. Copp, Tara. Federman, Josef. “Israel could have used smaller weapons against Hamas to avoid deaths in Gaza tent fire, experts say.” Associated Press. May 30, 2024.