TEHRAN – Lebanese media have reported that Hezbollah, the Lebanese Resistance movement, has provided its ally Iran with images and components of the advanced U.S.-made GBU-39B bomb.

Following the assassination last month of senior Hezbollah commander Haytham Ali Tabatabai by the Israeli regime, a GBU-39 smart, small-diameter bomb reportedly failed to explode. Hezbollah's security unit immediately moved into action, reportedly photographing the bomb, defusing it, and sending its essential electronic components to Iran for reverse engineering. This development reportedly concerned Washington, which has since demanded that the Lebanese government return the bomb's remains to the United States. 

Reports also revealed that U.S. warplanes used massive GBU-57 bunker buster bombs, each weighing 13 tonnes, during attacks on Iranian nuclear facilities in June 2025. One such bomb reportedly failed to detonate and subsequently fell into the hands of experts at the Iranian Defense Ministry. Iranian sources have since confirmed that Tehran has successfully reverse-engineered the giant munition.

Although Iran has reportedly replicated the massive GBU-57 bomb, its 13-tonne weight restricts its widespread use. Sources at the Iranian Defense Ministry indicate that accessing the lighter GBU-39B bomb (weighing around 100 tonnes) provided by Hezbollah is more vital for Iran’s missile doctrine. Iran reportedly intends to incorporate the penetration and guiding technology from that bomb into its ballistic missile warheads.

Iranian military engineers have now reportedly succeeded in designing a warhead similar to that of the GBU-57, intended for installation on “Fattah” hypersonic/ballistic missiles (with a range of 1,400 kilometers). Additionally, a more modern version is under development for the “Khoramshahr-4” missile (with a range of 2,000 kilometers). Field tests indicate the Iranian warhead can penetrate up to 20 meters deep into reinforced concrete and underground fortifications, though the American version reportedly achieves penetration depths of up to 60 meters.

Iran’s military arsenal is largely domestically produced. Some of its designs are now being replicated by other countries, with the Shahed-136 drone being one of the most copied weapons by several major arms manufacturers, including the U.S. itself. However, Tehran has, at times, reverse-engineered captured American weapons, including a Lockheed Martin RQ-170 drone that it safely brought down on Iranian territory through cyberwarfare in 2021.

Since the U.S. and Israel attacked Iran in June, the country has been intensively working to fill its military gaps and further advance its most important tools of defense: its missiles. These missiles forced Israel and the U.S. to ask for a ceasefire after they wreaked havoc in the occupied territories for 12 days. Despite tight censorship by Israel, a significant amount of footage has been released showing parts of Israeli neighborhoods in complete ruins. Israel has placed the majority of its military and intelligence infrastructure inside crowded neighborhoods.

Neither Iran nor Hezbollah officials have addressed the bomb transfer rumors. Washington’s demand that the government return the weapon, however, drew ire in Lebanon, with citizens pointing out on social media that the U.S. "shamelessly" wants the Lebanese to give back its undetonated bomb so it can use it to kill more people.

Hebrew media says Pentagon officials view the situation as “sensitive”, noting that even partial access to the bomb’s internal components could expose design methods that the United States relies on to support its modern strike arsenal.

American military blogs describe the GBU-39 as a lightweight, air-launched munition converted into a precision-guided bomb. It utilizes GPS-aided inertial navigation, enabling accurate strikes from long distances.