Why chemical weapons are so feared

Syria is in the firing line over claims the  used chemical weapons against civilians in its long-running civil war.

But the world is undecided on how to react – with the US stalling over a vote in Congress on military action against the regime. President Barack Obama backed off from armed intervention after Russia said it would work with Syria to secure its chemical warfare arsenal.

But US estimates suggest that Congress – amid uncertainty over who was responsible for a chemical attack in Ghouta near Damascus – would not have backed further military action in the Middle East.

The UK Parliament has already rejected a call by Prime Minister David Cameron to line up alongside the US to intervene – probably through the use of stand-off weapons, rather than an invasion. Raymond Hainey looks at what chemical weapons are and do – and why there is such international revulsion against their use. 

What chemical warfare capability does Syria have?

Huge. The country is estimated to have the third-largest stockpile of chemical weapons in the world, after the US and Russia.

Stocks include nerve agents Sarin, Tabun and VX, together with blistering agent mustard gas.

What are they?

Sarin and Tabun were developed in Germany in the 1930s as pesticides – but the then-Nazi regime saw their military potential and ordered them to be developed for military use in WWII, although they were never deployed.

VX – the most deadly synthesized nerve agent known – was created in the 1950s in the UK, also as a pesticide. It too was adopted by the military and later shared with the US, which also created weaponised verstions.

Mustard gas – originally called LOST – was developed for the German army in WWI and extensively used by both sides in the later stages of the war.

What do they do?

Nerve agents all act in the same way – they attack the central nervous system, causing breathing problems, convulsions and, depending on type used and exposure, often rapid death. It is thought that Sarin was the agent used in Ghouta, which caused as many as 1500 deaths.

Mustard gas causes severe burns to the body, attacks the eyes, causing temporary blindness and if inhaled causes severe burns, internal bleeding and permanent damage to the respiratory system and digestive system. In cases of severe exposure, death is common.

They can all be delivered in canister form, or by air-dropped bombs, artillery shells and rockets.

Why aren’t they banned?

Many countries have banned them. The international Chemical Weapons Convention is signed by 189 countries – although five countries, including Syria and North Korea, have not signed or ratified the agreement. Syria is now trying to do so. The US in the late 1960s promised to destroy their chemical weapons, although it has yet to work its way through its massive stocks. Russia is doing the same.

The UK renounced the use of chemical and biological weapons in 1958 and all stocks were destroyed.

Why are they so feared?

The reasons are complex — in the western world, images of WWI mustard gas and phosgene casualties are seared into the collective consciousness and the Nazi use of Zyklon B gas in the mass murder of millions of Jewish people and others horrified the world.

It is true that bombs and bullets also kill — but gas is seen as a particularly immoral way to wage war, with efforts to outlaw its use dating back to the 19th century.

The fact that gas attacks are usually invisible and indiscriminate also fuels public horror at their use. n