Although the end of the Cold War has led to a reduction in the armed forces, the US fleet of nuclear-capable bombers is still the largest and most capable in the world.
These bombers were part of the Strategic Air Command (SAC) until its abolition in 1992 then moved to Air Combat Command. On 7 August 2009, the new Global Strike Command came into existence, combining the B-52 and B-2 forces with the Minuteman missiles, with emphasis on the nuclear role. The initial plan was to declare it operational on 6 August, but it was realised that announcing a new nuclear command on the anniversary of Hiroshima was a really bad PR move.
It should also be noted that these bombers are now de-alerted- it would take a number of weeks to get them nuked up again.
This page focuses on dedicated bombers; many fighters and attack aircraft can also carry nuclear bombs, though their shorter range limits them to tactical roles.
Platforms that did not enter service in a nuclear role are listed in [Square brackets].
Bombers
B-29 Superfortress
The only nuclear launch vehicle to have actually been used to drop nuclear bombs in combat- the Enola Gay and Bockscar were B-29s. Very few B-29s were nuclear-capable. The specially-trained unit responsible for the bombings was equipped with purpose-built "Silverplate" B-29s. Modifications included adding a "weaponeer" position to monitor the bomb, filling the rear bomb bay with additional fuel tanks, and removing all the bomber's armor and defensive weapons. The B-29 was directly copied by the Soviets as the Tu-4 "Bull", after a bunch of them had to land in the USSR during World War II. As the Soviets were neutral at that time vis Japan (not entering until the very end), they confiscated the aircraft.
B-50 Superfortress
A variant of the Superfortress (originally designated the B-29D) equipped with more powerful engines (the engines used on the previous versions had a distressing tendency to overheat to the point of catching fire; the newer engines, among the most powerful piston engines ever produced for the aviation industry, were also more reliable). The designation change was made in order to skirt the post-World War II budget cuts.
B-36 Peacemaker
The successor to the B-29 in US service; it was probably the first truly intercontinental bomber. The jet engines of the era were still rather unreliable and fuel-thirsty, so it had six huge piston engines mounted in its wings, in a pusher configuration no less. The thing was huge; although it wasn't the heaviest, it was the largest combat aircraft ever constructed (the record for "heaviest combat plane" goes to the Tu-160 and there are larger transport aircraft). It carries what still qualifies as an enormous bombload (up to 86,000 pounds of ordnance). It dates back to the WWII era; the US was worried about the security of Airstrip One...err, the United Kingdom, and wanted a bomber that could reach targets in Europe from the North American mainland. (Admittedly, Sealion was a crapshoot at best, but that's another story.) There's just something about it, in terms of aesthetics it would fit nicely into BioShock if the game wasn't set underwater. Anyway, it was slow, especially compared to jet bombers like the B-47, although that one was somewhat short-legged and had to be based relatively close to the Soviet Union in order to reach its targets there. Later, in order to give them a higher dash speed over a target and through the worst of the Soviet air defenses, they were fitted with four jet engines in two underwing pods (2 engines per pod), so later variants had a total of ten engines, resulting in a joke about "six turning and four burning."note This was a truly huge airplane; if the Wright brothers started their historic first flight at one wingtip of a B-36, they would land short of the other wingtip. The wings were also so thick that there was room for a crawlspace allowing the crew to access and make repairs the piston engines in mid flight. Its sheer size, coupled with it being constructed mostly out of magnesium, led to its Fan Nickname of "Magnesium Overcast". Detractors, particularly in the Navy which saw it as draining funding away from their aircraft carriers, gave it the rather less flattering nickname of "the Billion Dollar Blunder".note
You might conclude from this hyperbolic talk about its size that the B-36 was a logistical nightmare. You would be right to do so. Its fuel requirements were enormous, it required airstrips longer and more heavily reinforced than were usual at the time, and its maintenance needs were horrific. One telling example: The maintenance instructions required that every sparkplug on its 6 piston engines had to be replaced after every flight. That amounted to 360 plug-changes every time one of these bastards landed.
It was even planned at one point to be an honest-to-goodness Airborne Aircraft Carrier, being used to launch and recover the tiny F-85 Goblin fighter. The Goblin, however, never made it into production, so the B-36 was never used in that role. This was followed up by a second attempt, the FICON (Fighter Conveyor) project in which the entire bomb bay of the RB-36 reconnaissance version was replaced by a "trapeze" to carry the full-sized RF-84K Thunderflash recon fighter.note These actually saw limited service (with 10 GRB-36 conversions and 25 RF-84K built), before being replaced by the U-2 spy planes. It also carried a ridiculous amount of defensive armament (The Other Wiki lists sixteen cannons). Later, though, the cannons (except for the tail guns) were deleted along with other stuff (including the never-utilized provisions for carrying a Goblin) in an effort (called the "Featherweight" program) to increase range and service altitude (afterwards, some of the Featherweighted B-36s were documented to reach heights of well over 50,000 feet—making them quite hard to intercept for a while, until fighter and SAM designs became advanced enough to allow for effective interception). An all-jet-powered, swept-wing derivative, the YB-60, lost the competition to the Boeing B-52.note
- It features in a Jimmy Stewart film called, appropriately enough, Strategic Air Command.
- Interestingly, it also remains the only mass-produced combat aircraft ever to have been capable of delivering the heaviest conventional bomb ever made: the T-12 "Cloudmaker" 19.776627 metric ton (43,600 lb) earthquake bomb. A single B-36 could carry two of them.
B-45 Tornado
A North American offering. SAC's first jet bomber, and the smallest aircraft ever to head the U.S. strategic nuclear bomber force (the FB-111 was smaller, but was never the primary U.S. nuclear bomber); a straight-winged aircraft (like most of the very early jets, and like very few military jets since), having been designed before the wartime German research on the advantages of swept wings at high Mach numbers became widely available. Entered service in the nuclear role in mid-1952, a few years after it debuted as a conventional bomber. Short-legged, being based in the UK. Short-lived; by the time it entered service, the B-47 (see below) had already demonstrated the superiority of a swept-wing design, and the B-45 was regarded for its entire production run as a stopgap until the B-47 could be put into service, with the 40 nuclear-capable B-45s being phased out after only a few years (although bombless reconnaissance versions remained in service somewhat longer).
B-47 Stratojet
A Boeing offering; a graceful looking jet bomber (the first U.S. swept-wing jet bomber, giving it a crucial advantage over competing straight-wing designs) and the ancestor of no less than three distinct aircraft: the B-47's larger brother, the B-52, the accompanying KC-135 tanker aircraft and the revolutionary 707 airliner. It entered service in 1953, quickly replacing the B-45, and served alongside the B-36 for a while before both were replaced by the B-52. They were rather short-legged, mostly being based in the UK. Variants with cameras were used for armed photo-reconnaissance (!) over the Soviet Union, including a really ballsy mass overflight of Vladivostok.
B-52 Stratofortress
This one's been around a while (1955 was when the first version entered service) and may stay around until about 2040. The aircraft has a massive range (about 10,000 miles without refuelling), a big carrying capacity and can fire stand-off cruise missiles. Far more widely known by a rather vulgar nickname that notes its size, weight, physical unattractiveness and the fact it is a very potent weapon. Remains the US's primary nuclear bomber (the B-1B no longer being able to carry nukes and the B-2 being limited in number). 94 B-52H bombers are left of the 744 built. Took a conventional role as far back as Vietnam (with an entire sub-type being converted for that role back then, because the thing couldn't carry enough bombs otherwise) and still used in that role today. All had tail-guns, but the remaining B-52H bombers have had these removed, as they're now not much use. During the Vietnam War there were however 2 verified instances of B-52 tail gunners shooting down Mach 2 capable MiG-21 fighters, so the tail guns earned their keep prior to the increasing range and reliability of air-to-air missiles rendering them obsolete.
The aircraft was used in the Gulf War (firing conventional cruise missiles while over Saudi Arabia), Afghanistan and Iraq. The fact that it has a massive radar-cross section is irrelevant in the latter.
The B-52's longevity is such that all remaining aircraft in service are considerably older than the men who fly them, and there's even one case
of a B-52 pilot whose father and grandfather were also B-52 pilots.
- Appearances and references to the B-52 are considerable- it's even the name of a cocktail. Most notably, Doctor Strangelove and as the basis for the Cool Plane series in the novels of Dale Brown. There's also a band you might've heard of.
- The nickname is allegedly BUFF, for Big Ugly Fat Fellow but this is actually a creation of the USAF Press Office. The original comes from when the first modified "big belly" B-52D (painted black) was delivered and a General exclaimed "Look at that Black Ugly F-Bomb". That aircraft was then nicknamed the BUF. In the interests of political correctness it was retconned to BUFF with a knowing hint that the F did not stand for Fella. The crews, however, refer to the aircraft as "The Gray Lady" and have been known to take offense at the BUFF nickname. "Miss Buffy" is just barely acceptable.
B-58 Hustler
Notable for its massive underfuselage weapons pod, the Hustler was capable of sustaining about Mach 2.2 for over an hour (setting a lot of records for the time) and was designed for a role in Europe. While also capable of carrying conventional bombs, operationally it never did. When improved Soviet air defences meant the thing had to fly low level (limiting the range still further), it became too expensive to upgrade and the things were taken out of service about 12 years after they'd arrived. Another noteworthy feature was its in-flight computer, nicknamed 'Sexy Sally'. The computer would give automated messages and warnings to the crew. You see, bomber crews back then were all-male, and research had found that a woman's voice was more likely to get a young man's attention during a stressful situation.
- Colour-reversed Stock Footage of B-58s is used in the first Fail Safe as the exterior of the Vindicator bombers.
- You can find an informational film about the Hustler hosted by an Air Force Reserves Brigadier General named Jimmy Stewart, who starred in a fair number of informational films produced for the Air Force during the Cold War.
[XB-70 Valkyrie]
A North American offering. The US was worried about how well their bomber force could survive in the face of Soviet air defenses; for a while, their answer was to fly higher and faster, and the XB-70 was the ultimate expression of this trend: a high-altitude Mach 3+ jet bomber which could generate lift by riding its own sonic shockwaves. In the late 1950s it was believed that improvements in SAMs and air defense technologies would overtake what was manageable and practical for a manned aircraft, putting the viability of the B-70 in question. The B-70 program was put on hold in 1958/59 while a thorough evaluation of this issue was conducted. This showed that the promised advances in surface-to-air missiles were not taking place and were unlikely to be attained any time soon. In fact, even today surface to air missiles have not reached the level of performance predicted in 1957 and the B-70 would still be beyond their effective reach. It was also claimed that the Valkyrie had radar and thermal signatures that were abnormally large. This also was incorrect; the B-70 did have a very large radar cross sections from the side but nose-on it had only 40 percent of the RCS of a B-52 and this could be cut still further by using radar absorbing materials already being used on the SR-71 and A-12. Nor was the production B-70 likely to be that costly; USAF figures for a 350 aircraft fleet with 60 reconnaissance RS-70s was about $18 million per aircraft. This was twice the cost of a B-52H or 50 percent more than a B-58A. What really killed the B-70 was the need for funds to develop a multi-role combat aircraft that eventually became the F-111. The two XB-70s that were built were very valuable research aircraft, and very much deserving of their moniker. (Although, in context as a nuclear bomber, "Valkyrie" (from the Old Norse valkyrja, "chooser of the slain") as a nickname was also petrifyingly literal.)
The XB-70 also has an interesting legacy in the Lensman Arms Race it touched off. The Soviet heard about it and developed the MiG-25, basically a missile-armed, Mach 3-capable pair of jet engines with huge wings to keep it from falling out of the sky, as a counter. They also decided that big, long-range, supersonic bombers sounded pretty cool and developed one of their own, the Tu-160 Blackjack (it is the biggest combat aircraft ever built and exceeds every other American bomber in both payload and speed.) The Americans, misinterpreting the MiG-25 as an air superiority fighter, developed the F-15 as a counter.note The Soviets then trotted out the Su-27 to deal with the F-15, the Americans trotted out the F-22 to deal with the Su-27... and the USSR collapsed. As it stands, America and the F-22 have won,though Russia and China are each coming up with their own equivalents in the form of the Sukhoi PAK FA and the Shenyang J-31, respectively. We should leave it at that, because the F-22 causes enough Flame Wars as it is.
B-1B Lancer
Known among the crews as the "Bone" ("B-ONE" spelled out). The B-1A project was terminated due to being too expensive, and Carter (although he couldn't really say it at the time) deciding to focus his efforts on the B-2 instead. Reagan restarted the project with some modifications (reducing the max speed and turning the plane into a low-level penetrator) as the B-1B, and in all 100 were built. 67 remain in service with others lost in accidents or cannibalised for parts. With a four-person crew (women have flown it into combat), it has been optimised for the conventional role- i.e. it no longer can carry nukes- and used in a number of conflicts as such. It has an internal bomb load of 37,000 kg, second only to the Tu-160. It could add another 27 tonnes externally, but this is both pretty much prohibited by START I (which also effectively bars the plane from carrying air-launched cruise missiles) and would compromise the quasi-stealth capability of the aircraft (though neither has stopped the USAF from hanging targeting pods at these points, partly because the Taliban don't have radar) - it's estimated to have a radar cross-section 1/50 of the similar sized B-52. A proposed upgrade, the B-1R, would fully recommission all external hardpoints, upgrade the radar to track air targets, and allow bombs to be interchangeable with air-to-air missiles to create the world's largest fighter plane (as well as giving it the world's most awkward nickname for an aircraft).
- Dale Brown features the B-1B a lot in his novels.
- It features in Never Say Never Again.
- One appears in Real Genius.
- And another in Transformers: Revenge of The Fallen
B-2A Spirit
The Stealth Bomber. It's not impossible to detect on radar, just extremely, extremely hard.note It was originally developed to drop nukes on the USSR (much the same as the preceding B-52 and B-1), with stealth technology being utilized because the older bombers were deemed to be too vulnerable to Soviet air defenses. The B-2 is still nuclear-capable and crews still train for the nuclear mission, but so far it has only been used in a conventional role. The B-2 did not become operational until after the Cold War ended, where its first combat use was in Kosovo. Since then it's been used in various conflicts, and it is notable for having flown the longest-distance bombing raids in history, usually from the continental U.S. to its target on the other side of the globe. 132 aircraft were originally planned, but with the end of the Cold War this was cut down to only 21, which contributed to a very expensive per-unit cost of $2.1 billion dollars per airframe (due to the same developmental costs being spread over fewer aircraft). One B-2 was lost to a takeoff crash caused by faulty instrumentation, so the fleet now stands at 20 aircraft, most of them based at Whiteman AFB. Because of the small size of the fleet and the high value of the aircraft, B-2s are individually named, more like ships than planes. The formula is Spirit of *US State*, e.g. the B-2 that crashed was the Spirit of Kansas.
- Used in the Dale Brown novel Sky Masters.
- Independence Day shows them attempting a nuclear strike on the aliens above Houston.
B-21 Raider
A stealth bomber under development by Northrop Grumman that looks like the company's B-2, but simpler and sleeker on the outside, and somewhat smaller and lighter.Nuclear-powered bomber proposals
That's right. As if arming them with nuclear weapons wasn't bad enough, they came up with a bunch of screwy proposals. They'd have had to carry a lot of shielding and seat the crew as far away as possible from the reactor, for obvious reasons. And it would probably be best if the crew didn't have too many children, for similarly obvious reasons. As insane as it may sound, it did offer some range and performance advantages; in the end, though, the concept was rendered obsolete by, among other things, ICBM technology. A modified NB-36 actually flew with a reactor onboard, although this was just a small 1MW model and the idea was to test the effects of radiation on aircraft systems and crew. The NB-36's reactor was not capable of powering the engines There was a proposed B-36 derivative, the Convair X-6, which would have been a bona fide nuclear flier. Eek.
- On the plus side, the Aircraft Reactor Experiment advanced nuclear reactor research in radical ways. Unlike conventional reactors that use solid fuel and water coolant, these reactors used molten salts to carry dissolved nuclear fuel. With the fuel as a liquid, it was like the reactors were burning gasoline instead of coal. These developments led to the highly successful Molten Salt Reactor Experiment over at Oak Ridge National Laboratory in Tennessee, which proved these reactor types were feasible as commercial power reactors. Sadly, funding was cut in the Seventies and the project largely forgotten, but MSRs have been revived as part of the Gen-4 reactor initiative. Particularly interesting is the Liquid Fluoride Thorium Reactor, a variant which gets most if not all its fuel value from thorium instead of uranium.
- Non-mobile molten-salt reactors actually have a tremendous safety benefit from using liquid fuel. In routine operation, there's an emergency drain-pipe that's plugged by blowing cold gas across a flattened section of the pipe, causing a plug of frozen salt to form in it. If the reactor overheats, or that blower loses power, the frozen plug of salt melts, and all the fuel-salt drains into a passively cooled drain-tank that is configured to prevent the nuclear reaction from continuing. In short, a molten salt reactor's entire failsafe mechanism is powered by the force of gravity, and if that has a Failsafe Failure, then a nuclear accident is the least of your worries!
F-111 Aardvark
The Aardvark (it only acquired its nickname formally at the retirement ceremony in 1996) was the world's first production swing-wing aircraft. A two-seater supersonic battlefield interdiction and deep-strike aircraft, it was exported to Australia and would have gone to the UK as a Vulcan replacement, but the latter was canceled due to budgetary reasons.
The F-111 was developed in the TFX (Tactical Fighter, eXperimental) program and intended for use by both the Air Force and Navy. The Air Force's version, the F-111A, was designed for low-level deep-penetration strikes against ground targets, while the Navy's F-111B was intended to be a carrier-based high-altitude interceptor— this was why it was given an F-for-fighter name rather than a B-for-bomber one. Ultimately the B model it was too heavy to land on carrier decks, and was abandoned in 1968. (The USN replaced it with the F-14 Tomcat, also a swing-wing fighter and the star of the movie Top Gun. Grumman, brought in to assist General Dynamics with the 'vark thanks to the former's experience with naval aviation, took their experience with the F-111B and applied much of what they learned to the Tomcat.)
The F-111A, meanwhile, turned up in Vietnam in 1968 for combat testing in real conditions, where three were lost, due to terrain-following radar problems rather than enemy action. Once those problems had been sorted out, it proved quite effective- it didn't need escorts. With progressive enhancements, it got even better. It featured in the 1986 attack on Libya and played a big role in Desert Storm in 1991.
It could carry free-fall tactical nuclear weapons (in an internal weapons bay or externally) and had provision for a defensive cannon. It was assigned to Tactical Air Command and some were based at RAF Lakenheath in the UK.
It is quite fair to say that the F-111 was one of the most feared US aircraft of the Cold War by the Soviet Union. Low-level performance was excellent.
- Features in the Dale Brown novel Chains of Command
- F-111s were used to deliver smart bombs to knock out assorted targets, in Tom Clancy's Red Storm Rising.
FB-111
The SAC version of the Aardvark, with up to 6 SRAMs and an increased wingspan to allow more fuel to be carried. It was capable of conducting strikes in the USSR, with tanker support, from the continental United States.
With the B-1B entering service, this became surplus to requirements and the end of the Cold War meant the aircraft were converted to become the F-111G, mostly used for training, with some passed to Australia.
Orbital Bombers
In the 1950s, there were proposals to develop an orbital bomber, launched via a Titan missile. Eventually, this changed into the X-20 Dyna-Soar (Dynamic Soarer), an orbital spy plane, which was eventually cancelled in favor of MOL (Manned Orbiting Laboratory), a spy space station. Finally, the USAF had pretty much all of their own manned space flight proposals cancelled in the late 1960s in favor of spy satellites, like Corona and the Key Hole series.
"Next Generation Bomber"
With the B-52, B-1, and B-2 due to be retired at some point in the future (like all machines, military aircraft only work for so long before they start to break down), the air force plans to have a new bomber to replace them. It will most likely be designated as the "B-3", but for the moment it's only officially known as the "Next Generation Bomber". Like the B-2 before it, the Next Generation Bomber will be stealthy and subsonic. There are plans for the plane to be optionally manned so that it can fly either with a pilot or as an unmanned drone. There is also ongoing discussion about whether the bomber should be nuclear-capable from the outset, as the current plan is to build the bombers without nuclear capability to save costs and then add it on later. Critics of this plan say that it will be cheaper in the long run to have nuclear capability built into the plane from the beginning rather than doing modifications at a later date. Lastly the Air Force wants to keep a lid on costs by making use of existing "off-the-shelf" technology, but the end result will likely still be a very expensive acquisitions program.
Air-launched Missiles
AGM-12 Bullpup
The first mass-produced air-to-surface missile, it could be steered via the launching pilot. A nuclear version was made.
- In the pilot of Airwolf, Dr Moffett fires one from the titular chopper and sinks a Knox-class frigate.
AGM-28 Hound Dog
Named after the Elvis Presley song. A nuclear-tipped stand-off weapon intended to be used by B-52s, so as to improve their survivability in the face of Soviet air defenses, some of the best in the world if stretched thin in some places. Had the drawback of being very large, such that a B-52 could carry at most two, and that only if it was stripped of all other bombs and armament; this forced the nuclear-armed B-52 fleet to be divided into aircraft carrying bombs (for attacking the bombers' primary targets) and aircraft carrying Hound Dogs (for taking out Soviet air defenses on the way in), obviously a less-than-optimal solution, and one which led to the development of the SRAM (see below).
AGM-48 Skybolt
A cancelled Air-Launched Ballistic Missile (ALBM)- yep... Was intended to be the successor to the Hound Dog. The British were also planning to go for this one for their Vulcans, and were rather outraged when the United States cancelled it without consulting them first. The outrage instantly vanished when the much more capable Polaris SLBM was sold to them for their Resolution class boomers instead.
ADM-20 Quail
It doesn't really count, but it's still worth mentioning; this was an air-launched decoy missile intended to be carried by B-52s. Obsolete by the early '70s, but before then, it was expected to be capable of fooling Soviet air defense radars into thinking it was a B-52. The nickname "Quail" came from the fact that its entire purpose was to be shot at.
AGM-69 SRAM (Short Range Attack Missile)
Designed to replace the Hound Dog, this missile could perform "one major maneuver" in flight, attacking stuff behind the bomber for example. Much smaller than the Hound Dog; a B-52 could carry up to twenty of these 200 KT warhead missiles, or a smaller number of SRAMs plus a payload of nuclear gravity bombs (allowing a bomber to blast its own way through opposing air defenses on the way to its ultimate target, which eliminated the need to dedicate B-52s to the anti-air-defenses role. "Short Range" was relative; they had a range of 200 km which is well above average for an air-to-ground missile but short for a strategic weapon. Retired in 1990, with safety concerns being the cited reason; the missile used a two-stage solid-fuel rocket motor, and the binder in the solid fuel deteriorated with age, to the point where many of the SRAMs developed cracks in their fuel (which would likely have caused the motor to explode upon ignition).
AGM-86 ALCM (Air Launched Cruise Missile)
An air-launched Tomahawk in many respects (though not to be confused with the actual air-launched Tomahawk which was tested but never went into service), capable of sustained low-level flying at subsonic speeds and a range of over 1,500 imperial miles. 5 or 150KT W80-1 warhead and pretty accurate, it's the main air-launched bomber weapon of the US today- carried by B-52s. The B-version is nuclear-equipped. Surplus of those have been converted into conventional missiles and used in several US conflicts. Several Soviet air defense systems, including the MiG-31 interceptor and the Tor surface-to-air missile, were created specifically to counter the threat of the ALCM.
AGM-129 ACM (Advanced Cruise Missile)
A stealth successor to the ALCM, using the same W80-1 warhead (the planned conventional AGM-129C version was never built), it had a range of over 2,300 imperial miles. While its radar cross section was tiny (comparable to a small insect), the ACM was considerably more expensive than the ALCM and thus was retired in 2012 (long before its originally planned 2030 retirement date) in order to meet the requirements of nuclear arms reduction treaties.
Nuclear Bombs
Mark 3
Basically the exact same design as the "Fat Man" implosion-type bomb, only it used uranium instead of plutonium.
Mark 4
Basically a mass-produced version of the "Fat Man" bomb, it entered service just in time for the Korean War if the Korean War ever came to that point. The only real difference between a Mark 4 and a "Fat Man" was in the production method, meaning that only a B-29 or larger could carry it, and typically only one. If an American bomber was carrying a nuke in the immediate post-WWII/Cold War period, it most likely would've been this (and again, the bomber would've by necessity been most likely a B-29).
Mark 6 and Mark 13
The last nukes to carry the design legacy of "Fat Man," the Mark 6 was an improved Mark 4 and the Mark 18 had the highest explosive tonnage rating for a fissile (non-thermonuclear) bomb in U.S. inventory.
Mark 17
The United State's first thermonuclear bomb, so large it could only be carried by a B-36, and was retired out of necessity when that aircraft in turn was retired.
After this
Most U.S. nuclear bombs had relatively short service lives; from this point on, the U.S. would settle on missiles for the delivery of strategic nuclear warheads, particularly ICBMs and SLBMs. If for some reason a strategic-level nuclear bomb had to be dropped on somebody, the protocol was to simply load-up a bunch of B61s or B83s into a B-52; considering how a B-52 can carry a lot of these things, it wound up being more effective than just dropping a single mega-nuke.
