Arthurista and weapons of mass destruction
The Commonwealth Defence Forces are known to possess nuclear and chemical weaponry. According to information released by the Arthuristan Ministry of Defence to arms control organisationsas of 2017, the number of warheads in active service is 330, of which 288 are considered to be 'strategic' weapons.
First efforts: 1940s-1960s
Arthurista tested its first atomic bomb, a gun-type uranium-based fission device with a yield of 15 kiloton known as 'Red Rivet', in the last weeks of the Great Fascist War. A second, identical device was intended to be dropped at a site just off-shore of the Fascist capital of Kingston to intimidate the last remnants of its forces into an unconditional surrender, but in the event it was not needed as the city was successfully stormed.
Arthurista mastered the capability to build implosion-based weapons in 1947. Over the next few years, atomic weapons of between 10-30 kilotons were manufactured in small batches at a leisurely pace, featuring non-standardsed 'physics packages' hand-assembled by skilled technicians. These heavy bombs were only capable of being carried by large strategic bombers, and the main carriers for these early weapons was the Victory Bomber, later replaced by the jet-powered Sperrin and finally, the Continental Imperator, of which 160 were procured. It was estimated that Arthurista possessed a stockpile of over 90 atomic weapons by 1951. All of these 'artisan' bombs would later be dismantled and their fissile material re-used for newer generations of weapons.
It was not until the 1953 that the 'Red Shoe', a standardised casing light enough to be carried by both bombers and tactical fighters, weighing 750kg with a variable-yield fission warhead of up to 60 kiloton, entered mass production.
Meanwhile, theoretical and experimental work towards creating a fusion-device continued apace. However, initially, there was little effort to develop such weapons, with both the military and political establishment believing that the existing fission bombs constituted a sufficient deterrent. The political decision to create thermonuclear weapons of real military utility was not made until 1956, prompted by the fact that purely fission weapons become prohibitively expensive to 'scale' up to larger blast yields, due to their consumption of large quantities of valuable fissile materiel for which far more productive uses could be found, such as fuelling power plants or naval vessels.
Fortunately, the theoretical and experimental groundwork for the creation of miniaturised thermonuclear weapons had already been laid earlier, albeit languishing unused until then. In 1961, the 'Red Hammer', a one tonne device with variants yielding from 0.5kt to 150 kt, and which could be carried by small fighters as well as heavy bombers, reached operational status and became the standard Arthuristan free-fall bomb. In 1963, bombers began to deploy with the ACM-3 Bune stand-off nuclear missile, significantly enhancing their survivability in the face of increasingly capable counter-air technology then gradually coming into service around the world.
Towards minimum credible strategic deterrence
By the early-60's, it was increasingly realised that a nuclear deterrence, based purely on bombers based in the open, was potentially vulnerable to a first strike. Realising that the costs associated with maintaining a fully-capable nuclear triad was unsustainable, the Ministry of Defence decided to migrate Arthurista's main strategic deterrence towards the least-vulnerable option, i.e. a submarine-based configuration. The focus of Arthuristan planners had evolved into emphasising the retention of a guaranteed 'second-strike' capability, in order to deter a first-strike by assuring the ability to impose a cost unacceptable to a potential aggressor in retaliation simultaneously to three of its most powerful potential adversaries. This spurred the development of the Reprisal-class submarine and the Bluemoon missile. Initially armed with a single high-yield warhead, improved SLBM's were soon available, incorporating MIRV technology and the 150kt Red Goblin warhead which, alongside the Red Hammer, remains one of Arthurista's two nuclear weapons to this day.
Currently, the main weapon deployed by the CDF is the Bluesun SLBM, which are deployed on Commonwealth Navy's four Styx Class ballistic missile submarines. Eliminating a land-based ICBM force also disincentivises an opponent from attempting a counterforce first-strike against mainland Arthurista.
In order to provide Continuous At Sea Deterrence (CASD), one of the four are always on patrol in peacetime, and there is a 50% chance that one additional boat is at sea at any given moment. Of the others in dock, one is undergoing maintenance/repair, with another on 'extended alert' or shore-side training. In wartime, the number of boats continuously at sea can be increased to three, although this may be detrimental to force readiness in the post-crisis period.
Arthurista has a longstanding qualified 'no first-use' policy, undertaking that it will not initiate the exchange of weapons of massed destruction outside of the Arthuristan mainland.
The CAF Bomber Command has maintained a small fleet of long range bombers. Although their current primary roles are maritime strike and long range tactical interdiction, they also retain their secondary role as delivery vehicles for strategic nuclear weapons using long-range cruise missiles or air-launched ballistic missiles. In an emergency, they will disperse into a number of pre-designated airbases, and certain squadrons would maintain a 24-hour aerial patrol, awaiting the signal to attack. They also have a tactical nuclear delivery role.
Current nuclear strategy
While Bluesun is certainly accurate enough for a counterforce first strike, the small quantity available dictates its use primarily as a countervalue weapon, used to threaten a potential aggressor's population centres. Arthuristan planners determined that, by the time a retaliatory second strike is to be launched, most of the enemy's strategic weapons would have 'flown the coop', rendering an attack on them pointless. Rather, the Arthuristan strategic arsenal would be used to systematically demolish the enemy nation itself. As the entire weight of Arthurista's strategic armaments is to be concentrated on cities, rather than divided between military and strategic targets, this allows a relatively small and inexpensive inventory of warheads and delivery system to achieve the same destructive effect (and thus deterrence effect) a much larger stock of nuclear weapons can inflict on strategic targets.
The stance of minimal deterrence was vividly described in 1985 by Rear Admiral Sir Charles Worthy, C-in-C Submarine Force, as follows:
"We no longer possess the capability to wipe out three of our most potent adversaries five times over, as we did ten years ago, even if they retain the ability to wipe us out five times over. All we require in order to deter a preemptive strike is the capacity to exact unacceptable cost but once. Everything above and beyond is gratuitous and wasteful overkill which is thoroughly unfair to the taxpayer."
This strategy is, naturally, highly controversial, though Arthuristan strategists and lawyers attempted to justify a plan premised entirely upon an attack on the enemy's civil population by positing that, after a first strike, densely-populated Arthurista would have suffered catastrophic civilian casualties in any case, regardless of whether these first strike weapons were aimed at military forces or deliberately targeted at cities, hence rendering the follow up Arthuristan strike a proportionate retaliatory measure.
It is notable that, of the enemy's population centres, only the very largest would be attacked, and the fact that they are targeted in the first place is much more due to political reasons rather than strictly military ones. It is envisaged that the bulk of Arthurista's warheads would instead be used to destroy ports, transportation hubs such as nodes of railways and motorways, as well as irradiating the enemy's agricultural areas with cobalt bombs, rendering them unusable for decades. The intended effects of this plan of attack is to maximise the effect of Arthurista's relatively small strategic arsenal by rendering the enemy nation unable to grow, transport or import food, thereby starving to death the majority of its populations without the need to directly target the smaller urban areas.
Tactical nuclear weapons
The aforementioned 'no-first-use' rule deliberately left unstated the position regarding the use of tactical nuclear weapons on the Arthuristan mainland. The use of tactical weapons in a defensive campaign against an invader has featured heavily in Arthuristan military theory since the 1960s. Their use in such a scenario is regarded as an issue for the military, rather than a purely political matter. Rules for their release are much looser and often left at the hands of relatively junior officers, commanders of divisions or even brigades. This is based on two assumptions. Firstly, it adds an element of unpredictability as to whether they might be used to counter a large-scale invasion, especially if, inevitably, higher headquarters are 'decapitated' by precision strikes in the course of high-intensity fighting. The army believes this unpredictability contributes towards their value in deterring a potential invader. Secondly, it demonstrates the confidence of Arthuristan strategists in the relative invulnerability of its submarine-based second strike capability and its value in deterring escalation to the strategic level by its ability to hold the enemy's homeland hostage.
Tactical nuclear weapons are ground-launched or air-launched. Corps commanders have access to the ACM-11 Lucifer theatre ballistic missiles, whereas at the Army-level the ACM-7 Astaroth MRBM and the ACM-1 Cerberus long range cruise missile. Air-launched tactical nuclear weapons are primarily carried by fighter-bombers.
Command and control
The command and control of Arthuristan nuclear weapons is notoriously simple. The commander of the submarine will order a missile launch upon receipt of a clear order to do so. Alternatively, where it is known that the nation has come under nuclear attack (there are tests which must be performed in order to confirm this state of affairs, such as whether a number of designated civilian radio channels are still broadcasting), and that no order has come from above, such as in the event that the nation's military and political leadership has been 'decapitated', the commander opens his sealed 'Letter of Last Resort', written by the Prime Minister on his/her first day in office, containing instructions on whether to retaliate, to refrain from doing so, or to place his or her vessel under the command of an allied navy.
Permissive Action Links are not used by the Arthuristan military. The submarine captain can easily effectuate a launch with the assistance of his executive officer and a few members of the crew. Tactical nuclear warheads are armed with a key, which is inserted into a lock "not dissimilar to those used to prevent bicycles from theft" according to one journalist.
Chemical and biological weapons
Arthurista built a stockpile of chemical weapons between the 50s-70s, mainly GB and VX nerve agents intended for use as tactical weapons. The program was accelerated in the wake of the Tempesta War. This policy was reversed in 1984, when a unilateral moratorium on the development of chemical weapons was declared and in subsequent decades the stockpile was reduced by more than 80%. Successive governments have reaffirmed the commitment to fully eliminate the stockpile by 2030 at the latest, though leaked plans from the Ministry of Defence may suggest that the elimination process has been paused since the mid-2000s. Presumably, the aforementioned undertaking to not initiate an exchange of WMDs beyond Arthuristan soil also governs the use of chemical weapons by Arthuristan forces.
Loweport has never opted to develop a biological weapons stockpile, except small quantities produced for the purposes of studying potential countermeasures. Biological agents were considered to be weapons of dubious military value: insufficiently fast-acting to be used as tactical weapons and no-match for a nuclear arsenal on the strategic level.