Chemical Weapson Essay Research Paper Title Chemical

Chemical Weapson Essay, Research Paper Title (Chemical Weapons): Terrorist Use of Chemical Weapons in the World Special Issue: The Tokyo Subway Attack on 20 March 1995

Chemical Weapson Essay, Research Paper

Title (Chemical Weapons): Terrorist Use of Chemical Weapons in the World

Special Issue: The Tokyo Subway Attack on 20 March 1995


Japan has long enjoyed the enviable reputation of being one of the safest nations in the world. The country has one of the world lowest rates for murder and other violent crime, and the Japanese National Police Agency and local Police forces are often praised as a model of law enforcement efficiency. Tokyo enjoys one of the cleanest, safest and most efficient subway networks in the world. Trains run on precise schedules and accommodate 2.7 billion passengers a year. All that changed on March 20, 1995. A nightmare unfolded as the city of Tokyo experienced one of the worst terrorist attacks of the century. This is what many considered to be the first true case of use of chemical agents by terrorists in a major attack on civilians.

On the morning of 20 March 1995, small containers described by eyewitnesses as being wrapped in newspaper and covered with clear plastic bags about the size of lunch box were placed on five trains running on three major lines of the Tokyo subway system (Marunouchi, Chiyoda, and Hibiya). The trains were scheduled to arrive at the Kasumigaseki station within four minutes of each other at the height of the morning rush hour around 8 am in the morning. It was to report later that police authorities suspected the containers to be a type of binary chemical weapons in which the constituent elements of sarin were brought together to form the poisonous gas just prior to its release by breaking of the bottles in the crowed cars. The results were twelve people dead and over five thousand injured, as gas spread through the trains and affected passengers were disgorged at sixteenth separate stations along the route. Two of the subway lines were shut down and twenty-six stations closed.

The station, towards which the cars were gathering, Kasumigaseki was located in the heart of Tokyo’s government area, which is close to many Ministries, and the National Police Agency (NPA) Headquarters. Some commentators began to think that the attack was targeted on NPA officers. Some commentators evidently anticipated that the Tokyo attack was a prelude to the issuing of demands by the criminal. Commentators also expressed surprise that, given the toxicity of sarin and the nature of the target, the casualty had not in fact been much higher. Others suggested that the agent may simply have been impure, perhaps deliberately diluted either self-protection of the attackers or to keep the number of fatalities low. This theory appeared confirmed by the discovery early on the traces of another substance, acetonitrile (or methyl cyanide), which it could have been used to dilute the gas.

Some Unexplained Incidents:

In the days following the subway attack, as the casualty toll continued to rise, the Amu Shinri Kyo (or “Supreme Truth”), whose leader- Shoko Asahara, had in the past shown an interested in chemical and biological warfare. Two days after the attack, large numbers of police officers began massive raids on the sects many facilities throughout Japan, on the pretext of searching for kidnap victims (since there was no immediate evidence linking it to the subway attack). At one location particular, a compound or commune at Kamikuishiki in the surroundings of Mount Fuji 100 km west of Tokyo, they discovered extensive facilities for the manufacture of chemical weapons and huge stockpiles of the chemicals themselves, including all of the necessary ingredient for the manufacture of sarin. However, despite repeated searches over many days, the authorities were unable to come up with a “smoking gun” linking the sect directly to the Tokyo Subway Attack.

But there had been a series of unexplained incidents leading up to the subway attack that might have suggested that terrorists were experimenting with poisonous gas. The most significant of these occurred in the mountain resort of Matsumoto, 125 miles northwest of Tokyo, late in the evening of 27 June 1994. A substance later identified as sarin seeped through the open windows of apartments and houses, killing or injuring every living inside an area 500 yards long by 100 yards wide. Seven people died and 264 were injured. Suspicion initially fell on a former chemical salesman at whose residence various chemicals were seized, and who was believed to have released the gas accidentally in attempting to produce a homemade herbicide. However, police later dismissed him as a suspect and continued unsuccessfully to pursue what they considered to be a murder investigation.

A few months after the Matsumoto incident (but not reported until after the Tokyo attack), in September 1994 an anonymous letter had been sent to the Japanese media, hinting that nerve-gas attackers could target the Tokyo Dome. The letter was also said to have “correctly predicted that the next target would be Tokyo’s subways”. One listing of previous incidents notes, without providing any further details, that on 1 September 1994 “more than 230 people in western Japan suffered rashes and eye irritation from unknown fumes” (JT 1995). In a more widely-reported case, late on 5 March 1995, a colorless gas had filled a train car on the Keihin Kyuko rail line between Yokohama and Tokyo and overcome 19 of 80 passengers, the victims complaining of headaches, blurred vision and nausea. Eleven had been hospitalized, but there were no fatalities. According to one report: “Police and firefighters searched the car but found nothing suspicious” (JTW 1995). Just ten days later, on 15 March 1995, authorities in Tokyo found three attached cases at the Kasumigaseki subway station holding “containers of clear liquid, a powerful battery-operated vaporizer and a fan to blow the resulting vapor through vents”: at least one of the cases was emitting a kind of vapor. Although the liquid in question proved to be water, authorities reportedly stepped up security at the station afterwards.

Sarin Gas:

Sarin, (also known as GB, isopropyl methylphosphanofluoridate) is a colorless and odorless gas, has a lethal dose of 0.5 milligram for an adult. It’s 26 times more deadly than cyanide gas and is 20 times more deadly than potassium cyanide. Just 0.01 milligram per kilogram of body weight a pinprick sized droplet can kill a human. The vapor is slightly heavier than air, so it floats close to the ground. Under wet and humid weather conditions sarin degrades swiftly, but as the temperature rises up to a certain point, sarin increases it’s lethal duration. It was discovered by G. Shrader in Germany in 1939.

National & International Impact:

The attack on the Tokyo subway system had a major impact on Japan itself and international community. The government immediately came under criticism for having failed to move sooner against Aum Shinri Kyo or to solve the earlier cases of sarin poisoning. Later that month, fear of a possible chemical attack led to the mobilization of up to 60,000 police officers throughout Japan. Police would notice thousands of tourist spots across the nation, keeping a close watch on hotels, amusement centers, railway stations and underground shopping malls. Everybody in the country was talking about what was happening among them.

The Tokyo subway attack also created ripples abroad. Security was tightened in subway systems in different cities, including New York, Washington, Milan, Rome and especially the South Korean cities- Seoul. Just two days after the Tokyo attack, there was a similar scare in Seoul when at least ten people were taken to hospital after “mystery gas fumes” leaked through several floors of a 19-storey office building. However, the following day it was announced that a backflow of carbon monoxide into a boiler vent had “probably” been responsible. The Seoul subway system was still on emergency alert a month after the Tokyo attack, the number of police officers on its patrol squad having been increased from 260 to 1,300.

One other international connection that at first appeared relatively innocent but later proved to be quite disturbing was the sect’s purchase in 1993 of a remote sheep ranch, Banjawarn Station, in Western Australia near Leonora, variously described as being 400 or 745 miles northeast of Perth. In September 1993, two members of an Aum Shinri Kyo group arriving in Perth. They directly involved in sarin attacks—were arrested and fined $2,400 each for carrying dangerous chemicals on an aircraft, after customs officials found two black plastic containers of hydrochloric acid labeled “hand soap” in their luggage. In addition, Aum Shinri Kyo had imported two large crates of chemicals and equipment (including “a few test tubes and laboratory gear”), ostensibly for gold- prospecting purposes. According to one report: “Customs officials confiscated the chemicals which, apart from hydrochloric acid, were listed as assorted chemicals, acids and chemical solutions’ and were apparently not analyzed at the government laboratories in Perth.” The report added that “Australians who had dealings with the group were reported to be mystified as to why they paid so much to fly in chemicals and gear easily obtainable in Western Australia ” (AFP 1995).


The important thing to remember about this incident is that it was a let off, a warning. There is the potential for a far more serious incident. The raw materials are reasonably easy to get. Having said this only a small amount is required if the dispersal method is efficient. In this incident the dispersal was not efficient enough, which resulted in saving many lives. Unfortunately when terrorists get control of weapons, as they have no government or subjects to answer to allowing them to be as irresponsible as they like. For these reasons the supply of the raw materials must be more tightly controlled. Even though the raw materials can be kept in the same containers as other legitimate chemicals all that is required is a rigorous testing procedure.



AFP- Agency France Press, “Japanese Sect Members Spent Lavishly in W. Australia: Report” (1995).

JT -Japan Times, “Other Toxic Fume Cases” (1995).

JTW -Japan Times Weekly International Edition, “Security System Getting a Hard Look: Murayama” (1995).

DARSC- , published by the Aum Shinri Kyo sect on 1995.