Cruise missiles that are difficult to detect, increasingly fast and capable of carrying nuclear warheads are spreading, especially in Asia, complicating arms control and raising the risk of catastrophic conflict.
Until recently, most concerns have focused on the actual or potential spread of nuclear-tipped ballistic missiles in China, North Korea, India and Pakistan — the four Asian states known to have atomic arms. Ballistic missiles, launched by rocket engines, follow an arc-like trajectory, attaining hypersonic speeds on the downward leg of their guided journey towards a target.
Until now and probably for some time yet, all long-range ballistic missiles, with atomic warheads small enough to fit on them, are deployed exclusively for strategic nuclear deterrence. The five official nuclear weapon states — United States, Russia, China, Britain and France — use their long-range ballistic missiles, whether launched from land, air or sea, to deter possible attacks by other nuclear-armed nations.
Arms control treaties and agreements have tended to focus chiefly on ballistic missiles. However, another type of weapon, the cruise missile, is multiplying. It is proving to be even more difficult to control, partly because in many cases the same highly accurate missile is designed to carry either a conventional high explosive warhead or a nuclear warhead.
This dual role makes it impossible for a nuclear-armed nation facing a cruise missile attack against its territory or warships to know whether the incoming weapons are conventional or nuclear, an uncertainty that could trigger a nuclear response. Dual-role ballistic missiles of less than intercontinental range pose a similar problem.
The U.S. Air Force Global Strike Command reported last month that both China and North Korea were developing nuclear-capable cruise missiles. The U.S. and Russia lead the world with nuclear-capable cruise missiles, weapons launched from long-range bombers or submarines. But India and Pakistan are also developing such missiles. They each have several different types, with different ranges, in service or being flight tested.
Cruise missiles, powered by jet engines, travel low and fast over land or water, making them difficult to detect. They are also relatively small, compared to long-range ballistic missiles.
There are about 1,140 of the nuclear version of the U.S. AGM-86 air-launched cruise missile in America’s nuclear arsenal. In addition, there are about 460 nuclear-capable AGM-129A advanced cruise missiles. The U.S. Air Force says that the streamlined design of the AGM-129A, combined with radar-absorbing material and several other features, make it virtually impossible to detect on radar.
The range of the U.S. AGM-129 A is officially put at almost 3,220 km. However, the nuclear-ready version of Russia’s Raduga Kh-101 air-launched cruise missile, which is due to become operational this year, is designed to have a maximum flight distance of just over 9,650 km, which puts it in the range category of an intercontinental ballistic missile.
The new Chinese and North Korean cruise missiles appeared on a slide of an unclassified briefing given by Lt. Gen. James Kowalski, head of the U.S. Air Force Global Strike Command, on May 7. The slide shows nuclear weapon modernizations in eight of the world’s nine states known to have atomic arms. Only Israel is not shown.
The Chinese cruise missile is the CJ-20 carried by the long-range H-6 bomber. Hans Kristensen, a nuclear weapons specialist with the Federation of American Scientists, said the listing was the first he had seen in an official U.S. publication crediting a Chinese air-launched cruise missile with nuclear capability.
U.S. defense officials say that a Chinese extended range H-6 bomber using the CJ-20 in a land-attack operation could strike targets all over Asia and eastern Russia as well as the U.S. military base hub on Guam island, in the western Pacific. Two-thirds of Russian territory, east of the Ural mountains, is in Asia.
The nuclear-capable North Korean cruise missile listed on the briefing slide is the KN-09 for coastal defense. It reportedly has a range of just 100 to 120 km.
America’s AGM-86 nuclear-tipped cruise missiles travel at just over two-thirds the speed of sound.
Meanwhile, India is looking to its supersonic Brahmos cruise missile, a joint venture with Russia, as the key new weapon that will give it a strategic advantage over its neighbor and long-time rival, Pakistan. The Brahmos is the only known supersonic cruise missile system in service. Its designer, BrahMos Aerospace of Russia, says it travels at two to three times the speed of sound, or approximately one kilometer per second.
In October, India and Russia agreed to produce more than 1,000 Brahmos missiles for the Indian Air Force, Navy and Army. The two sides also decided to jointly develop a hypersonic version of the missile that would fly more than five times the speed of sound.
The Indian missile, which can be launched from the sea, air or land, has a range of about 300 km. It can carry a conventional or nuclear warhead. The high speed of India’s Brahmos cruise missile means it has the potential to carry out prompt strikes on extremist camps inside Pakistan, to be followed by a punitive invasion by the Indian armed forces.
Because India is so much bigger and stronger than Pakistan, the latter has developed short-range ballistic missiles with low-yield nuclear warheads to deter such attacks. Although still to be verified, Pakistan claims it has miniaturized nuclear warheads so that they will also fit on cruise missiles. India also says that its cruise missiles are nuclear-capable.
The short-warning time should either country use such weapons against the other means that escalation into an all-out nuclear exchange could result.
Shyam Saran, convener of India’s National Security Advisory Board, said in April that in a crisis with Pakistan, India would not be the first to use nuclear weapons. He warned that even if India was attacked with relatively small, or tactical, nuclear arms, it would “engage in nuclear retaliation that will be massive and designed to inflict unacceptable damage on its adversary.”
There is a wider warning here for Asian countries with tactical nuclear-tipped cruise or ballistic missiles in operation or planned. If ever used, such weapons could open a Pandora’s Box of horrendous consequences, proving that a limited nuclear war is a contradiction in terms.
Michael Richardson is a visiting senior research fellow at the Institute of South East Asian Studies in Singapore.