How Best to Destroy Iran’s Nuclear Sites: The Upgraded B61-12 Warhead
America’s new B61-12 nuclear warhead highlights how dangerous of a moment the world finds itself in—and real the potential is for unintended consequences, as the nuclear genie, however small, gets out of the bottle.
During the Cold War, both the Americans and their Soviet rivals were constantly innovating new ways to utterly destroy each other, notably in the arena of nuclear weapons development. One such American technological leap was the creation of the B61 nuclear warhead.
As of December 2024, the United States successfully completed a massive upgrade of these systems worth $9 billion. Indeed, this upgrade comes as the United States and Israel are potentially set to launch a devastating air war upon the Islamic Republic of Iran, as fears abound in Jerusalem and Washington that the Iranians are perhaps only a handful of days away from achieving nuclear capabilities.
In fact, during the first Trump term in office, the Department of Defense (DoD) altered its war plans for Iran that called for the use of these nuclear weapons against suspected hardened nuclear weapons development facilities in Iran. According to high-profile anti-war activist Scott Ritter, the best course for the Iranians would be to immediately halt their nuclear program—as this fear of a nuclear Iran is driving the Israelis and their American allies into potentially deploying terrifying systems such as the recently upgraded B61-12.
The History of the B61-12 Non-Strategic Nuclear Warhead
The B61-12 represents the fusion of legacy nuclear technology with modern precision capabilities. The B61 has evolved through 13 variants, since entering service in 1968, at the height of the Cold War. The B61-12 is the latest iteration. Unlike a wholly new weapon, the B61-12 reuses warheads from the B61-4, integrating them into a new casing equipped with advanced non-nuclear components.
The upgraded B61-12 weighs around 825 pounds and measures 12 feet in length. The weapon features a Boeing-designed tail kit, with an Inertial Navigation System (INS) and four maneuverable fins.
This upgrade effectively evolves a “dumb,” unguided gravity bomb into a guided weapon with a circular error probable (CEP) of just 30 meters. That’s a dramatic improvement over the 110–170-meter accuracy of earlier variants, such as the B61-11. Thanks to the inclusion of this Boeing-designed tail kit, the system’s pre-upgrade parachute system was removed, thereby ensuring safer aircraft separation and enabling both ballistic and guided drop modes.
B61-12s have been certified for deployment on multiple platforms. These platforms include the F-15E, the F-16, the F-35A, the B-2 Spirit, and NATO’s Tornado jets. The Pentagon intends to make their new B-21 long-range stealth bomber, the replacement for the aforementioned B-2 Spirit long-range stealth bomber, compatible with the B61-12, too.
Bear in mind that the United States may have anywhere from seven-to-nine B-2 Spirits based in Diego Garcia, a massive American and British military staging area in the Indian Ocean that is well within striking range of suspected Iranian nuclear facilities.
A standout feature of the B61-12 is its variable yield, adjustable between 0.3, 1.5, 10, and 50 kilotons. This flexibility allows military planners to tailor the bomb’s destructive power to specific targets, thereby minimizing collateral damage compared to higher-yield predecessors, like the B61-7 (360 kilotons) or the B83-1 (1.2 megatons). Hence, why it is important to contextualize this weapon’s upgrade with the ongoing nuclear crisis between Iran, Israel, and the United States.
Why Did America Upgrade the B61, Anyway?
Interestingly, it was not Iran’s nuclear threat that likely necessitated the upgrading of America’s B61-12 arsenal. Indeed, it was likely America’s old obsession with its longtime foe in the Kremlin that prompted the upgrade. Notably, the Americans accelerated the deployment of B61-12s to Europe in 2022, the same year that Russia invaded neighboring Ukraine.
The Americans have stationed around 100 B61-12s at NATO bases across Europe, along with an additional 100 in storage. The upgrade bolsters the alliance’s nuclear sharing program, where allied pilots could potentially deliver U.S. warheads in a crisis. Indeed, some anti-war activists have criticized this deployment as inimical to a peaceful resolution to the Ukraine War. They argue that the presence of the B61-12s negates peace talks, as it is perceived in Moscow that Washington would not be the only voice determining how—and when—to use these weapons.
America’s B61-12 upgrade was viewed by members of the National Nuclear Safety Administration (NNSA), which oversees the management of America’s nuclear arsenal, as paving the way for the creation of the B61-13, a more powerful and advanced variant than even the upgraded B61-12.
Anti-nuclear weapon voices point out that the increased precision and extremely low yields of the upgraded B61-12s make the use of nuclear weapons in a modern war setting more likely, perhaps ending the general taboo against using nuclear weapons in modern warfare that has persisted since 1945.
The $9 billion B61-12 upgrade is part of a larger $1.5 trillion nuclear modernization effort over 25 years. During the upgrade of the B61-12s, Congress intervened, as initial estimates for the cost of the B61-12 upgrade were $7.6 billion but had ballooned to $9 billion. Despite the cost overrun, Congress deemed the program too important and continued its development.
Are There B61-12 Warheads at Diego Garcia Right Now?
As for the question of whether nukes, even very low-yield systems like the upgraded B61-12, would be used as part of any serious strike package by the United States directed against suspected Iranian nuclear weapons sites, is speculative. So is the notion that the United States military is basing B61-12s at Diego Garcia. We just don’t know.
However, it must be noted that “support for nuclear-capable military platforms is a key function of Diego Garcia,” according to the Lowy Institute. “The remote base regularly hosts U.S. nuclear-powered cruise missile submarines (SSGNs) and submarine tender ships. Elements of America’s airborne leg of its nuclear triad also frequent the Indian Ocean atoll.”
So the probability that B61-12s are at least temporarily housed at Diego Garcia is fairly high. What’s more, the fact that Diego Garcia is not subject to the African Nuclear-Weapon-Free-Zone (Pelindaba) Treaty is yet another indicator that Washington has no compunction about utilizing this facility to conduct massive—and potentially even nuclear—strikes against hardened Iranian nuclear facilities that conventional bunker-busting bombs might not be able to destroy.
The B61-12 Could End the Nuclear Taboo
The decision by Congress to endure the cost overruns of the B61-12 upgrades makes more sense, when one realizes how appealing these weapons are to American strategists who are intent on preventing rogue regimes like Iran from acquiring nuclear weapons of their own. Of course, it highlights how dangerous of a moment the world finds itself in—and real the potential is for unintended consequences, as the nuclear genie, however small, gets out of the bottle.
Unlike the end of the Second World War, when the world came to a rapid consensus that the use of nuclear weapons should be avoided at all costs, in 2025, 80 years after the bombs dropped on Hiroshima and Nagasaki, the use of low-yield nukes by the Americans just might induce other nuclear powers to aggressively use their own weapons to finish off whatever foreign conflicts they are mired in. Prime Minister Netanyahu is surely watching. So is President Putin.
About the Author: Brandon J. Weichert
Brandon J. Weichert, a Senior National Security Editor at The National Interest as well as a contributor at Popular Mechanics, who consults regularly with various government institutions and private organizations on geopolitical issues. Weichert’s writings have appeared in multiple publications, including the Washington Times, National Review, The American Spectator, MSN, the Asia Times, and countless others. His books include Winning Space: How America Remains a Superpower, Biohacked: China’s Race to Control Life, and The Shadow War: Iran’s Quest for Supremacy. His newest book, A Disaster of Our Own Making: How the West Lost Ukraine is available for purchase wherever books are sold. He can be followed via Twitter @WeTheBrandon.
Image: Wikimedia Commons.
