Means of delivery
Depending on from where they are deployed, means of delivery can be categorized into land-, air- and sea-based systems or, based on their function, in air defence, sea- or land-based cruise missiles.
Very different means of delivery can be used for nuclear, biological or chemical weapons, such as pieces of artillery, missiles, cruise missiles, aircraft, helicopters or torpedoes. Various systems, such as aircraft with cruise missiles or submarines with torpedoes or cruise missiles can also be combined with each other. Not all systems are suitable for delivering the various kinds of weapons of mass destruction. Long-range ballistic missiles, for instance, are a highly uneconomic means of transport for chemical weapons and are hardly suitable for the use of biological weapons. While pieces of artillery can fire chemical or nuclear weapons in local fights, they are not suitable for nuclear weapons with high explosive power. Still, all these delivery systems had been used for one or more kinds of weapons of mass destruction. As the military usefulness of chemical and biological warheads is relatively small, the following reflection focuses on delivery systems for nuclear weapons.
Some mobile weapons platforms, so far used for conventional weapons only, can also be used as delivery systems for nuclear weapons. These are, for example non-nuclear submarines that carry long-distance sea-based cruise missiles with a nuclear warhead. From their advanced position, they can attack targets in far away countries, hundreds or even more than thousands of kilometres off the coast.
Drones, too, that can carry heavier loads, would theoretically also be able to do this. Technical progress will allow smaller nuclear powers to also build such relatively cost-effective means of delivery. To limit, reduce and eliminate delivery systems has repeatedly been the focus of arms control and disarmament treaties between Russia and the United States, as it is easier to check on the existence or destruction of means of delivery than that of nuclear warheads or atom bombs. This is why they were the main starting point for all strategic arms control efforts so far, the results of which are laid down in the SALT-, START-, SORT- and New START agreements. The Open Skies Treaty also starts with the means of delivery. All agreements contain detailed arrangements on limiting means of delivery yet hardly any regulations on their nuclear warheads.
For decades now, there have been efforts to make the spread of means of delivery more difficult or to curb it. The Missile Technology Control Regime (MTCR), established in 1987, is a voluntary agreement with which most countries that were capable of making means of delivery committed themselves to stopping the export of such systems (ballistic missiles, cruise missiles, drones) with a range of more than 300 km and a payload of more than 500 kg and to preventing the transfer of components and manufacturing technology for such systems. In 2002, this agreement was supplemented by the Hague Code of Conduct to which 134 member states have committed themselves politically—but not legally—to counter the spread of ballistic missiles and to be transparent with regard to their missiles. This code of conduct, however, does not apply to cruise missiles and drones.
Despite all efforts to keep the number of countries with means of delivery with sufficient payload for nuclear weapons small, the number of countries possessing such systems is growing. Today, more than ten countries respectively possess ballistic missiles with more than 300 km range and a load of more than 500 kg or cruise missiles of comparable specifications. More countries are developing such weapons or try to purchase the technology needed.
Tactical and strategic nuclear weapons
Strategic nuclear weapons, on the one hand, used to be weapons that the United States and the Soviet Union would have been able to fire at each other, directly and with a massive explosive power. Tactical weapons, on the other, are those that were designed to be used on battlefields such as in Europe and Korea with small, moderate or larger explosive power and that would not necessarily have resulted in a global nuclear confrontation including the United States or the Soviet Union. In the framework of the nuclear Strategic Arms Limitation Talks (SALT) agreements, nuclear weapons were defined as 'strategic' whose land-based delivery systems could deliver a nuclear warhead on targets 5,500 km or more away. Then, the nuclear means of delivery of the classical 'triad' were listed. Heavy strategic bomber with nuclear bombs or cruise missiles, land-based intercontinental ballistic missiles (ICBMs) and sea-based long-range submarine-launched ballistic missiles (SLBMs).
In this light, all five classic nuclear powers still use strategic means of delivery. The United States and Russia possess land-, sea- and air-launched systems. In the New START treaty, they agreed to limit the number of their strategic means of delivery to a maximum of 800 operational systems each by 2018 and to reduce the number of deployed strategic nuclear warheads to 1,550. China, Great Britain and France have markedly less than 100 strategic delivery systems and have so far maintained one kind of system each. China is in the process of using SLBMs in addition to ICBMs.
Each strategic system has its advantages and disadvantages from a military point of view: ICBMs can be positioned in silos (stationary) or on lorries (mobile). They are ready to be deployed within a short span of time, have short flying times, and there are no reliable means of intercepting them. Their disadvantage is that their positions are known and that they, therefore, become a primary target for the enemy. This is why the owner will be prepared to have these weapons ready for takeoff at all times and to launch them before they can be destroyed on the ground. If this were to occur due to a false alarm, the danger of a 'nuclear war by accident' would become real. Once launched, a missile can no longer return.
Sea-based long-range submarine-launched ballistic missiles (SLBMs), too, can quickly attack targets with multiple warheads at nearly all distances; only in the recent decades, though, have they have become as precise as ICBMs. Their greatest advantage is the fact that they are virtually invulnerable. Once launched, SLBMs cannot return, either.
But what about nuclear weapons with shorter ranges that were positioned on forward operating bases outside of the US or USSR territory and that could also constitute a threat to the mainland of both super powers? Weren't they strategic nuclear weapons, too? The Cuban Missile Crisis has shown very clearly that this was a severe problem. The political debate on so-called retrofitting gave rise to this question again in the 1980s. Both crises only found their political end when both sides renounced positioning missiles in forward positions and when they, finally, even agreed to a bilateral ban of land-based weapons with a range between 500 and 5,500 km in 1987 in the INF-Treaty. Nuclear weapons on forward positions that can attack the same targets as strategic long-range ballistic missiles continue to be a serious problem.
Looking at tactical and strategic nuclear weapons independent of the Russian–US American relationship, this artificial differentiation becomes even more apparent. When considering the deterrence ratio between Pakistan and India, India and China, France and Russia, nuclear weapons with a range far less than 5,500 km can indeed be strategic weapons. The distance between Islamabad and New Delhi is less than 700 km; between Beijing and New Delhi, it is about 3,800 km, and between Paris or London and Moscow, it is approx. 2,500 km. Russia is particularly affected by this scenario. Besides the three Western nuclear potentials, it also has to take into account those of China, Pakistan and India. There is about 3,650 km between Moscow and Islamabad. One can hardly say that just because states do not possess any intercontinental missiles, they do not possess any strategic nuclear weapons. Which nuclear weapons are considered to be strategic or tactical also lies in the eyes of the beholder.
From this, however, one cannot deduct that there are no tactical nuclear weapons. It is reasonable to say that a nuclear mine, an air defence missile or short-range ballistic missile with a nuclear warhead or a nuclear artillery shell for howitzers are tactical or battlefield weapons. During the Cold War, nearly all nuclear powers had such nuclear weapons. The superpowers possessed more than ten thousand of these each and used various means of delivery; all smaller nuclear powers together possessed less than one thousand of these weapons. Towards the end and after the Cold War, these holdings were quickly and substantially reduced. Many means of delivery were, therefore, no longer used for nuclear weapons.
All eight nuclear powers of today (plus North Korea should it own functioning nuclear warheads) possess or used to possess non-strategic nuclear weapons. The overwhelming majority of the weapons still in use today are medium-range missiles—somewhere in-between a typical battlefield weapon and a strategic weapon that indeed has a range of more than 5,500 km. Many of these weapons are atomic bombs and nuclear missiles for tactical fighter-bomber aircraft or medium-range ballistic missiles that can be deployed over variable distances of up to one thousand kilometres. After the end of the Cold War, NATO countries initially called all non-strategic Russian nuclear weapons tactical weapons. With this, they implied that Moscow would use such weapons to wage war as long as it benefited from this militarily on a tactical or operative level or it would be able to prevent its inferior conventional troops from being defeated. In contrast, NATO referred to its nuclear weapons as sub-strategic arms to point out that the role of these weapons was predominantly a political one in the framework of deterrence. Since the NATO summit in 2012, however, both Russian and Western nuclear weapons of this kind are referred to non-strategic weapons.
