General Confirms Enhanced Targeting Capabilities of B61-12 Nuclear Bomb


By Hans M. Kristensen

The former U.S. Air Force Chief of Staff, General Norton Schwartz, confirmed last week that the B61-12 nuclear bomb planned by the Obama administration will have improved military capabilities to attack targets with greater accuracy and less radioactive fallout.

The confirmation comes two and a half years after an FAS publication first described the increased accuracy of the B61-12 and its implications for nuclear targeting in general and the deployment of U.S. nuclear weapons in Europe in particular.

The confirmation is important because the 2010 Nuclear Posture Review (NPR) pledged that nuclear warhead “Life Extension Programs…will not support new military missions or provide for new military capabilities.”

In addition to violating the NPR pledge, enhancing the nuclear capability contradicts U.S. and NATO goals of reducing the role of nuclear weapons and could undermine efforts to persuade Russia to reduce its non-strategic nuclear weapons posture.

Confirmation of the enhanced military capability of the B61-12 also complicates the political situation of the NATO allies (Belgium, Germany, Italy, the Netherlands, and Turkey) that currently host U.S. nuclear weapons because the governments will have to explain to their parliaments and public why they would agree to increase the military capability.

Desired Military Capability

General Schwartz’s confirmation came during a conference organized by the Stimson Center in response to a question from Steven Young (video time 49:15) whether the relatively low yield and increased accuracy of the B61-12 in terms of targeting planning would change the way the military thinks about how to use the weapon.

General Schwartz made his statements during a Stimson conference last Thursday.

General Schwartz’s answer was both clear and blunt: “Without a doubt. Improved accuracy and lower yield is a desired military capability. Without a question.”

When asked whether that would result in a different target set or just make the existing weapon better, General Schwartz said: “It would have both effects.”

General Schwartz said that the B61 tail kit “has benefits from an employment standpoint that many consider stabilizing.” I later asked him what he meant by that and his reply was that critics (myself included) claim that the increased accuracy and lower yield options could make the B61-12 more attractive to use because of reduced collateral damage and radioactive fallout. But he said he believed that the opposite would be the case; that the enhanced capabilities would enhance deterrence and make use less likely because adversaries would be more convinced that the United States is willing to use nuclear weapons if necessary.

Military Implications

“Nuclear capable aircraft may have many advantages. Accuracy (as compared to other systems) is not one of them,” the Joint Staff argued in 2004 during drafting of the Doctrine for joint Nuclear Operations. Test drops of U.S. nuclear bombs normally achieve an accuracy of 110-170 meters, which is insufficient to hold underground targets at risk except with very large yield. The designated nuclear earth-penetrator (B61-11) has a 400-kiloton warhead to be effective. Therefore, increasing the accuracy of the B61 to enhance targeting and reduce collateral damage are, as General Schwartz put it at the conference, desired military capabilities.

Increasing the accuracy broadens the type of targets that the B61 can be used to attack. The effect is most profound against underground targets that require ground burst and cratering to be damaged by the chock wave. Against a relatively small, heavy, well-designed, underground structure, severe damage is achieved when the target is within 1.25 the radius of the visible crater created by the nuclear detonation. Light damage is achieved at 2.5 radii. For a yield of 50 kt – the estimated maximum yield of the B61-12, the apparent crater radii vary from 30 meters (hard dry rock) to 68 meters (wet soil). Therefore an improvement in accuracy from 100-plus meter CEP (the current estimated accuracy of the B61) down to 30-plus meter CEP (assuming INS guidance for the B61-12) improves the kill probability against these targets significantly by achieving a greater likelihood of cratering the target during a bombing run. Put simply, the increased accuracy essentially puts the CEP inside the crater (see illustration below).


Cratering targets is dirty business because a nuclear detonation on or near the surface kicks up large amounts of radioactive material. With poor accuracy, strike planners would have to choose a relatively high selectable yield to have sufficient confidence that the target would be damaged. The higher the yield, the greater the radioactive fallout.

With the increased accuracy of the B61-12 the strike planners will be able to select a lower yield and still achieve the same (or even better) damage to the underground target. Using lower yields will significantly reduce collateral damage by reducing the radioactive fallout that civilians would be exposed to after an attack. The difference in fallout from a 360-kiloton B61-7 surface burst compared with a B61-12 using a 10-kiloton selective yield option is significant (see map below).

Illustrative difference in radioactive fallout from a 360-kiloton B61-7 surface burst against Iranian underground enrichment facility at Fordow, compared with using a lower-yield option of the B61-12. Fallout calculation from NUKEMAP at Click image to see larger version.

No U.S. president would find it easy to authorize use of nuclear weapon. Apart from the implications of ending nearly 70 years of non-use of nuclear weapons and the international political ramifications, anticipated collateral damage serves as an important constraint on potential use of nuclear weapons. Some analysts have argued that higher yield nuclear weapons are less suitable to deter regional adversaries and that lower yield weapons are needed in today’s security environment. The collateral damage from high-yield weapons could “self-deter” a U.S. president from authorizing an attack.

There is to my knowledge no evidence that potential adversaries are counting on being able to get away with using nuclear weapons because the United States is self-deterred. Moreover, all gravity bombs and cruise missiles currently in the U.S. nuclear arsenal have low-yield options. But poor accuracy and collateral damage have limited their potential use to military planners in some scenarios. The improved accuracy of the B61-12 appears at least partly intended to close that gap.

Implications for NATO

For NATO, the improved accuracy has particularly important implications because the B61-12 is a more effective weapon that the B61-3 and B61-4 currently deployed in Europe.

The United States has never before deployed guided nuclear bombs in Europe but with the increased accuracy of the B61-12 and combined with the future deployment of the F-35A Lightning II stealth fighter-bomber to Europe, it is clear that NATO is up for quite a nuclear facelift.

AN-1 First Flight Aerials
Once European allies acquire the F-35A Lightning II it will “unlock” the guided tail kit on the B61-12 bomb. The increased military capability of the guided B61-12 and stealthy F-35A will significantly enhance NATO’s nuclear posture in Europe.

Initially the old NATO F-16A/B and Tornado PA-200 aircraft that currently serve in the nuclear strike mission will not be able to make use of the increased accuracy of the B61-12, according to U.S. Air Force officials. The reason is that the aircraft computers are not capable of “talking to” the new digital bomb. As a result, the guided tail kit on the B61-12 for Belgian, Dutch, German, Italian and Turkish F-16s and Tornados will initially be “locked” as a “dumb” bomb. Once these countries transition to the F-35 aircraft, however, the enhanced targeting capability will become operational also in these countries.

The Dutch parliament recently approved purchase of the F-35 to replace the F-16, but a resolution adopted by the lower house stated that the F-35 could not have a capability to deliver nuclear weapons. The Dutch government recently rejected the decision saying the Netherlands cannot unilaterally withdraw from the NATO nuclear strike mission.

It is one thing to extend the existing nuclear capabilities in Europe; improving the capabilities, however, appears to go beyond the 2012 Deterrence and Defense Posture Review, which decided that “the Alliance’s nuclear posture currently meets the criteria for an effective deterrence and defense posture.” It is unclear how improving the nuclear posture in Europe will help create the conditions for a world free of nuclear weapons.

It is also unclear how improving the nuclear posture in Europe fits with NATO’s arms control goal to seek reductions in Russian non-strategic nuclear weapons in Europe. Instead, the increased military capabilities provided by the B61-12 and F-35 would appear to signal to Russia that it is acceptable for it to enhance its non-strategic nuclear posture in Europe as well.

Such considerations ought to be well behind us more than two decades after the end of the Cold War but continue to tie down posture planning and political signaling.

See also: B61 LEP: Increasing NATO Nuclear Capability and Precision Low-Yield Nuclear Strikes

This publication was made possible by grants from the New-Land Foundation and Ploughshares Fund. The statements made and views expressed are solely the responsibility of the author.

10 thoughts on “General Confirms Enhanced Targeting Capabilities of B61-12 Nuclear Bomb

  1. Hans Kristensen:

    Absolutely the best article yet on the B61-12 project; scope and intentions. At last, a clear understanding of the military and political (deterrence) ramification of this weapon system. Changed my mind on the subject.

    Question regarding B61-12 aircraft. Understand the “digital” B61-12 isn’t compatible with current older NATO F-16A/B and Tornado PA-200 aircraft. Thus, those legacy aircraft that currently serve in the nuclear strike mission will not be able to make use of the increased accuracy (digital targeting ability) of the B61-12 bomb. Also, it’s clear in your post as new F-35 are introduced in NATO, the enhanced targeting capability of the B61-12 will become operational. Italy, Turkey and the Netherlands are scheduled to purchase the new F-35s; Belgium and Germany are not. Indeed, Belgium in the future may purchase F-35s to replace its inventory of F-16s but that’s far from a given. Germany has no intentions of ever purchasing the F-35. I’m under the assumption that the digital software/hardware of the B61-12 can be adapted to any airframe. Thus, Germany could use an “updated nuclear capable” Typhoon aircraft in the NATO Nuclear Mission in the future. Is that your understanding? Or, would it be a political possibility that by replacing the existing B61-3/4s and introducing the B61-12 in Europe, Germany would end its NATO nuclear mission?

    Frank Shuler


    1. Thanks for the roses. Concerning the B61-12 compatibility with Tornado and F-16A/B, as far as I understand it they can and will receive some upgrade. Apparently, although this is still a little murky, there is a difference between the aircraft’s computer talking to the bomb and the tail kit itself. So the upgrade will allow the aircraft to arm and deliver the B61-12, but the Air Force people I talked to said the tail kit will be locked on those aircraft. I had heard this was the case for the Tornado but it was a surprise that it apparently also affects the F-16A/B. This initial tail kit constraint is similar to what other analysts, such as Otfried Nassauer, have heard from European officials.

      1. Great article.

        Any idea what the difference is between the mod12 tail kit and JDAM?

        It seems strange that F-16 and Tornado are JDAM capable and could arm B61-12, but can’t interface with mod12 tail kit.

  2. “But he said he believed that the opposite would be the case; that the enhanced capabilities would enhance deterrence and make use less likely because adversaries would be more convinced that the United States is willing to use nuclear weapons if necessary.”

    +1 on what he said. Anything we can do to make nuclear weapons less likely to be used (including making them more capable) is a good thing in my mind.

    I agree with Frank though – good write up. My one concern is using the word of a retired Air Force General as confirmation. Was he speaking in an official role as a representative of the US government at the event? Do we know how connected he is to the B-61-12 effort? “Confirmation” just seems a little strong to use when you are quoting a retiree who may or may not remain directly connected to the effort.

  3. Keith, I second your comments. I don’t think the weaponry supports new military missions per se but simply updates deterrence, which is the stated mission and history of the program. It does seem to provide for new military capabilities, as Hans points out, which may be just a war over words or may in fact be more than such. At any rate, I appreciate the info that Hans has well presented, as usual.

  4. @ Hans and Frank

    Sorry, I didn’t see your conversation earlier. Here’s what might take it a little further. To my understanding, the German AirForce is not yet capable to fully understand the requirements for integrating the B61-12 into the Tornado, since the technical parameters are not yet known in a manner detailed enough. Thus integration is perceived to be primarily a US-responsibility for the time being.

    Tornado electronics are currently undergoing an upgrade to ASSTA 3.0 standard for 85 (+5?) aircraft to be maintained until to 2025 plus. Industries prepares another upgrade to standard ASSTA 3.1 for implementation from 2018 onward. While both upgrades might be seen as “some digitalization”, as far as I understand, they do not have any connection to integrating the B61-12, This would come at a later point of time, when requirements for the new bomb become available and known. Let me add, it is also my understanding, that the GAF could use the Tornado well beyond 2030 and possibly beyond 2035, making further upgrades of the electronics attractive,

    @ Hans

    To my understanding the B61-12 onboard a Tornado wil be more accurate than the B61-4 onboard the Tornado, however it would not be as accurate as the B61-12 on a JSF.

    @ Frank

    The Eurofighter-DCA is a theoretical dream of some transatlantic political analysts, costing some underexaggerated € 250-500 million. To my understanding industries is not willing to offer the US the technical insight required for nuclear certification.

    @ both

    At the same meeting Gen Schwartz argued, that the money preplanned to make the JSF dual capable, would be better spent on the future LRSB, if the Europeans wouldn’t share the financial burden. Does one of you believe this to be realistic? I don’t think so, and I believe the two of you don’t do so either.

  5. @ Frank and Hans

    one more addition. To my current understanding the B61-12 onboard a legacy aircraft such as the Tornado will be somewhat more accurate than a B61-4 with its parachute. However it will be not as accurate as a B61-12 onboard a fully digitalized aircraft such as the Joint Strike Fighter, which can make full use of its TKA.

  6. Ok going to explain this out really easy in as simple terms posable.
    Gravity Well Bomb (GWB) For mining.
    Dont even bother reading this unless you understand advanced math.

    Ok going to explain this out really easy in as simple terms as able to.

    First off triangle. The strongest shape going. So a 1 foot triangle with three rods, one in each corner. On each rod 3 dumb bell shape weights hooked up to a gear on each. Made so the weight can spin around while on the rod. Maybe a foot tall for each rod. One weight near the bottom close to the triangle. One weight in the middle of the rod and one weight near the top. Maybe abec bearings to make the weights spin faster.
    Top and bottom weight must spin the same way and middle weight must spin the other direction. Otherwise you have a completely different device.
    Hook up gears on weights to a means to make them spin. Either a bike chain hooked up to a small engine or use other gears hooked up to a small engine. May want to use three small engines, one for each tier of spinning weights. Each tier will have three weights. So you will have a total of 9 weights spinning. Also you will want to run a current of electricity threw the rods.
    In the center of the triangle raised up to the level of the middle weights put a ruby with a way to strike it with a needle very hard and fast. So the ruby fractures and makes the desired sound.
    Ok Currents causes a electromagnetic field.
    Weights cause a gravity well
    Ruby cause the vibration inside the well.
    So spinning weights explained. Getting them to spin at about the power of 1 will give you a total power of 3 in the center.
    Look at it this way. if you take a pal of water and put it on its side the water falls out
    But if you spin the same pal of water around faster and faster slowly bringing it up the pal will be at its side and the water will not fall out.
    So basicly you are looking at you arm to the end of the bucket being the length.
    Then the weight of the water.
    The rpm that it takes to spin it around and keep it in the bucket.
    now doing this with the weight works the same way but no water. The ends of the weights have the gravity force of 1 ok. You can’t see this force but it is there.
    Now with all three weight spinning you have a total of 3 on top and 3 on the bottom holding in the 3 in the middle. The top and bottom will run off up and down but will keep pressure on the one in the middle. The well in the middle will become stable.
    So if you have a 1 foot well that would be from the center of the weights to the center of the triangle.
    Ok so maybe you have already learned the take a 1 foot balloon into the water thing but I will explain it again. If you blow up a balloon to 1 foot in size and take it down 33 feet of water it will be 1/2 its size due to the pressure. Another 33 feet and its a 1/4 its size. so yet another will make it 1/8 its size.
    So 1, 1/2 2, 1/4 3, 1/8 4, 1/16 5, 1/32 6, 1/64 7, 1/128 8, 1/246 9, 1/542 10, 1/1082 11, 1/2164 12, 1/4328 13, 1/ 8656 14, 1/17312 etc etc. you see how its builds up.
    If there are 5280 feet in a mile then at 14 atm thats over 3 miles. that little 1 foot balloon would want to grow to the size of.

    You are now pushing in on the center well with 3 atm like this. So that 1 foot gravity well will want to expand to 8 times its size.
    The current will charge the atoms.
    Striking the ruby in the center will cause a tone that it takes to fracture a lv ten stone. Different sounds different results. Very usable for mining to remove lesser stones. A level 8 stone will leave behind all level 9-10
    After the stone is stuck the sound wave given of from it will shake the atoms in the given space going back and forth over and over till in the weights and rods break apart. The electric charge will demagnetize the atoms. The rods will shatter and the well will be released. Everything in a 8 foot area will be shaken apart to a single atom state in a perfect circle from the center of the triangle.
    Atoms take a short time to repolarize and reform material.
    Putting a faster spin on things will give larger results.
    Do not use light instead of sound. Sound at least stops at space. Light dose not and burns the atoms.

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