After the advent of nuclear weapons, the two superpowers suddenly possessed the ability to alter the very conditions for life. Hiroshima and Nagasaki shook the foundations of international relations. Even the most pragmatic and incisive scholars of power, like Hans Morgenthau, thought world government was now an urgent moral necessity (if not soon actually in the offing).
We look at the world so much through this post-nuclear weapons, post-World War II lens—what Hannah Arendt identified as the transition from the problem of mass death to the problem of evil—that the immensity of what preceded it in that century, and has postdated it in our own, has gone by curiously unremarked. It's true that we are living in the nuclear age, with the weapon of mass destruction par excellence. But the Bomb has only been used twice, by the same country, in the last 70 years. Only nine countries possess nuclear weapons. They are exceptional in more ways than one.
But the use of another WMD, chemical weapons—the "poor man's atomic bomb," as the saying goes—has been disturbingly pedestrian. Chemical weapons maim civilians indiscriminately. Their effects can fairly be described as torture. They are weapons of terror as much as war, which provides unique advantages in conflict as well as in "pacifying" civilian populations. Indeed, during the 1960s, Soviet plans for the invasion of Europe involved the extensive use of nerve gas, as the blanketing of civilian centers with chemical weapons would leave key infrastructure intact. Chemical (and biological) warfare is the only kind that exclusively targets living things.
Chemical weapons have been used in almost every decade since their advent just over a century ago. They are not a specter, like nuclear weapons. We know their effects, and how numerous states have employed them, and how they might do so in the future. In fact, after a few decades of relative non-use, chemical-weapons attacks have again exploded onto the scene—as a weapon of war, terror, and as a tool of state assassination. Their flexibility is part of their unique power.
Today, there is an international legal regime, surrounding the Chemical Weapons Convention (CWC), and an associated watchdog body, the Organization for the Prohibition of Chemical Weapons (OPCW), tasked with regulating treaty compliance. No CWC signatory—and there are 193 states-parties—is allowed to use chemical weapons, or even stockpile them. But in the last half-decade, that hasn't stopped these states from using them. Nor, because of great power politics, has this chemical weapons counter-proliferation regime been able to adequately deter non-signatories, or their enablers.
Despite recent saber-rattling by the Trump administration on North Korea's nuclear program, the likelihood of nuclear exchange between states is low. (Because of the consequences of such an exchange, this is a low-probability event that has to be treated as an exigent threat.) Yet the use of chemical weapons will likely continue unabated. It is unclear what this will mean in a world where the Western liberal order is fraying from the inside, China is rising, and Russia is renascent, but the most likely answer is: a weakening of the post-cold war chemical weapons counter-proliferation regime. And this could have consequences for international peace and security for decades to come.
The era of WMDs began not with a bang, but a hiss. Germany, which before World War I had the planet's most advanced chemical industry, quickly sought to weaponize its advances in this area. As early as 1914, Germany considered inserting chlorine—a powerful irritant and choking agent—into artillery shells and gas cylinders. The very first modern chemical attack occurred at Ypres, Belgium, on April 22, 1915. German troops fired cylinders containing 150 tons of chlorine at unsuspecting French soldiers, with whom they were engaged in a deadly war of attrition. A slow-moving cloud—released when the winds were favorable—wafted across no man's land to French entrenchments. The chlorine burned the lining of French troops' bronchial tubes. It caused blindness, uncontrollable coughing, nausea, headaches, and stabbing pains in the chest. Some of the exposed soldiers simply choked to death.
An (inevitable) arms race between the Allied and Central powers followed, but Germany had a significant head start. By Armistice Day, both sides had tested 3,000 different chemicals for their potential as weapons. And what actually made it to the battlefield was used prodigiously: combatants employed 124,000 metric tons of chemical weapons, delivered by 66 million artillery shells, over the course of the conflict. Exposure to gases caused one million casualties, including 90,000 fatalities. Many exposed to gases were permanently disabled.
Chemical weapons killed, but sometimes that wasn't even their main purpose. Mustard gas, a powerful blistering agent and skin irritant, was only introduced onto the battlefield (again, by Germany) in 1917, but its outward effects were so horrific—even though exposure to it was rarely fatal—that its usefulness as a weapon of terror was immediately apparent. (Individuals exposed to phosgene, which was by far the deadliest gas used in WWI—and was responsible for 85 percent of all gas-related deaths during that war—did not manifest outward symptoms the same way, and so its role is oddly forgotten today. Exposed individuals were often asymptomatic for hours, then their lungs filled with fluid and they died rapidly.)
The use of chemical weapons was likely already illegal under international law before World War I, but that didn't stop either side. Custom—first codified in the Franco-German Treaty of 1675—previously forbid the use of poison in war. In 1874, over a dozen European states signed (but did not ratify) the Brussels Declaration, which prohibited the use of poison gas and poison in conflict. Then, in the 1899 Hague Convention on the Laws of War, the European powers again agreed to refrain from using poison in war. States even signed a separate statement there, called the Hague Declaration Concerning Asphyxiating Gases, which outlawed the use of projectiles whose "sole object" was gas warfare.
During World War I, the Germans and subsequently the Allies violated, if not the letter, than the spirit of this law, by claiming that since their sides' chemical projectiles were "not solely" for the delivery of gas—a soldier might be injured by the artillery shell carrying the poison gas, you see—they were not contravening the 1899 Hague Declaration.
After the war, this spirit of formal compliance and informal hypocrisy lived on in the 1925 Geneva Protocol on Asphyxiating, Poisonous and Other Gases, which sought to actually make all uses of chemical weapons illegal in war.
All the great powers (excepting the United States and Japan) quickly ratified the proposal, but voluntarily opted for a poison pill: signatories reserved the right to use chemical weapons in retaliation for another state's chemical attack, and did not consider themselves bound to the treaty if engaged in hostilities with a non-signatory. (The protocol also did not forbid chemical weapons stockpiling and development.)
The treaty was vitiated within a decade. Fascist Italy, seeking to establish a colonial empire in Africa, waged a vicious war against Ethiopia in the 1930s. Mussolini's troops used chemical weapons, including mustard bombs, extensively on Ethiopian villagers in 1935 and 1936. Chemical weapons caused 15,000 of the 50,000 total Ethiopian casualties in the war, according to Soviet estimates. The use of mustard gas—which targets unexposed skin—was particularly cruel, as Ethiopian soldiers and civilians often did not wear shoes. (The high number of Russian chemical weapons casualties in World War I—425,000—was also largely due to the troops' lack of protective gear.) Though Italy's actions were a flagrant violation of the 1925 Protocol, the League of Nations did nothing.
And Italy wasn't the only contemporaneous chemical-weapons perpetrator. During its invasion of China during World War II, Japan dropped mustard gas and other chemical-weapons bombs on Chinese soldiers and civilians, killing at least 2,000 and injuring 35,000, according to archival research in both countries. (This, combined with Germany's widespread use of gas in its genocide of European Jewry, should put to bed the canard that poison gas was somehow not part of World War II.)
Although chemical weapons were not ultimately employed on the European battlefield during World War II, Axis and Allied powers both manufactured tens of thousands of tons of chemical weapons during the war. There was a forgotten arms race, wherein the "balance of terror" held the other side in check. But while the Allies refined older-model gases like phosgene and mustard, the Germans invented a new, far deadlier category of chemical weapons—nerve agents. (In one of the greatest intelligence coups of the war, the Nazis successfully kept this development secret from the Allies until their surrender. If they had chosen to use these weapons on Allied troops, they might have altered the course of history.)
Once again, Germany had its superior chemical industry to thank. Chemists from IG Farben, then one of the world's largest corporations, stumbled on compounds of extraordinary potency while trying to develop potential insecticides for commercial use. What became Sarin, Tabun, and Soman—all nerve gases, which cause the cascading failure of body functions, including the body "forgetting" to breathe, and then rapid death—were developed by German scientists working with their Wehrmacht counterparts.
Because of their power, nerve gases augured a new era in chemical weapons, leading to yet another arms race—this time between the U.S. and its allies and the Soviet Union, which sought to develop ever-deadlier and more persistent nerve weapons and delivery systems for them. By 1957, the U.S. had stockpiled so much Sarin domestically that it turned to developing the next-generation of nerve gases—known as "V" (for venomous) agents—selecting one agent, VX, for widespread production. VX was three times more toxic than Sarin when inhaled, and a thousand times more toxic when absorbed through the skin: theoretically, one liter of VX contained enough individual doses to kill one million people. In the late 1950s, Soviet intelligence secretly obtained the formula for VX, and started producing it domestically.
The USSR was a major proliferator of chemical weapons in the cold war, especially through its then-ally Egypt, which itself became a chemical weapons superpower. (To this day, Egypt refuses to sign the Chemical Weapons Convention, citing Israel's status as an undeclared nuclear power.) According to published reports, in the 1960s, Egyptian army officers traveled to the USSR for military training related to offensive chemical weapons.
Egypt rapidly used this knowledge. In 1963, it began using phosgene and mustard gas in its war against Yemeni royalist forces. Through 1967, Egyptian forces used chemical weapons—including nerve gas—in Yemen. Cyrillic marking on some bombs dropped by Egyptian troops led analysts to believe that the Soviet Union had either provided Egypt with nerve gas, or was using Yemen as a testing ground for it.
By the mid-1970s, the Soviets had developed a new class of nerve agents—known as the Novichok series—that were the most powerful ever invented. Testing showed some of these agents to be up to eight times as deadly as VX. To this day, Russia has denied ever possessing a weapon of its own invention.
But when it came to effecting mass casualties, earlier generations of chemical weapons—which had proliferated widely across the Middle East—were more than sufficient. (Starting in the 1970s, Egypt helped kick start the Syrian, Libyan, and Iraqi chemical weapons programs.) In 1980, Iraq, seeking oil wealth, launched a bloody war with Iran. From 1983 onward, Saddam Hussein's troops used chemical weapons extensively, including mustard, Tabun, Sarin, and VX, against its Iranian antagonists. Iran claims that 60,000 of its soldiers were treated for injuries related to exposure. (30,000 still suffer from effects today, say the Iranians.)
In 1988, Saddam followed his war with Iran with a brutal ethnic cleansing campaign against Iran-allied Kurds in Iraq's north. In the Iraqi city of Halabja, Saddam's troops carpeted the city with a cocktail of mustard, Sarin, and VX gases, killing up to 5,000 and injuring 10,000. The assault on Halabja, which has been called the single biggest chemical weapons attack on civilians in history, provides a taste of what a large-scale chemical "pacification" campaign in an urban area might look like today.
The U.S., deeply hostile to the Iranian regime, was muted in its criticism of Iraq. Muddying the waters, Reagan administration officials even speculated publicly that Iran might have been responsible for the gas attack at Halabja.
Because of the end of the cold war, the 1990s presented a rare moment of opportunity on chemical weapons. The Chemical Weapons Convention (CWC), borne on the back of negotiations between the two superpowers in the 1980s, went into effect in 1997. Prohibiting both the use and possession of any chemical agents designed for military use, it was an international legal landmark. The OPCW helped track states' compliance with the treaty, verifying states' commitment to safely destroy their existing chemical-weapons stocks.
Aside from the horrific 1995 Tokyo Subway Sarin attack by the millenarian Aum Shunrikyo death cult, that decade, and the one that followed it, were blessedly free from chemical attacks. (According to credible public sources, corrupt Russian government and military officials provided Aum Shunrikyo with the necessary technical knowledge and training. Russia's role in proliferation in this context has gone oddly unremarked.) And Saddam Hussein—until his 2003 overthrow, the greatest extant chemical weapons threat—was contained by multilateral sanctions and U.S. deterrence power. Now, Saddam is long gone. But in the last half decade, the scourge of chemical weapons came roaring back.
When the Syrian Civil War began in 2011, few were naïve about the Ba'athist regime's willingness to slaughter its own people. In 1982, Syrian president Hafez al-Assad—father of Bashar al-Assad, the current Syrian leader—brutally suppressed an Islamist revolt in the Syrian city of Hama, besieging and destroying whole parts of the city. An estimated 20,000 people were killed.
Nor was it a surprise that Syria had an extensive stockpile of chemical weapons. At the beginning of the war, it was one of the world's few holdouts on the CWC, and had long refused to sign the treaty. Syria, long considered a chemical weapons superpower, viewed its capacity to inflict mass death via gas warfare as a necessary deterrent against Israel.
But it was nonetheless shocking when the Assad regime decided to use these weapons on its own people. By late 2012, there was credible evidence that Syrian loyalist forces had used chemical weapons on rebel groups. In August 2013, Assad loyalists blanketed the rebel-held Damascus suburb of East Ghouta with Sarin, killing over 1,000 people, mostly civilians. The Obama administration, which had previously drawn a "red line" around the use of chemical weapons in the conflict, wavered on a military response after threatening targeted strikes at Assad regime facilities. With U.S. and international support, the Russian government then brokered a deal that would place Syria's declared chemical weapons stocks under UN and OPCW control. According to the deal, these weapons would be removed from the country and ultimately destroyed, and Syria would accede to the Chemical Weapons Convention.
But although Syria's declared chemical weapons stocks were ostensibly destroyed, the attacks continued. In some cases, Assadist forces appeared to use barrel bombs containing chlorine, which, because of its many commercial uses, is not banned under the CWC. In others, Assadist forces appeared to have continued to use nerve gases. In 2017, in Syria's Idlib province, regime forces used Sarin in an attack that killed 83 people. In 2018, 80 were killed in a gas attack, likely chlorine as well as nerve agents, perpetrated by the regime in Douma. According to estimates, the Assad regime has authored at least 50 separate chemical attacks over the course of the war. Over this period, Syria's key ally in the conflict—Russia—has defended it at the UN Security Council, OPCW, and other international bodies, preventing further punitive action.
Russia's facilitation of the breakdown of the norms and laws surrounding chemical weapons doesn't end there. In March 2018, an ex-Soviet spy and defector to the U.K., Sergei Skripal, and his daughter, Yulia, were nearly killed in their English village by exposure to Novichok, the Soviet-produced nerve agent that ranks among the deadliest in the world. Russia—and particularly its spy services—is widely considered to be behind the attack. An innocent English couple also picked up the discarded nerve agent in a park; the woman, Dawn Sturgess, died soon after exposure.
(Russia is not the only country recently to use chemical agents to assassinate dissidents or perceived threats to the regime; North Korea used VX to assassinate Kim Jung Nam, North Korean leader Kim Jong Un's half-brother, at Malaysia's Kuala Lumpur International Airport in February 2017. North Korea, which is not a party to the CWC, is thought to have begun its weapons program in the 1960s with technical assistance from the Soviet Union and China.)
The global chemical weapons counter-proliferation regime is at a crossroads. A signatory to the Chemical Weapons Convention, Syria, has continued to indiscriminately use nerve and other gases on civilian populations, killing thousands, in what can reasonably be described as war crimes and crimes against humanity. Syria's international sponsor—Russia—also a signatory to the CWC, has prevented international action to coordinate an effective response and deterrent to the Assad regime. Russia—which has declared itself chemical weapons-free—clearly lied about its stockpiles, since its agents attempted to use a deadly nerve agent in the middle of an English city. Russia has never even admitted to possessing the series of agents—Novichok—that it itself invented in the 1970s, and used to try and kill the Skripals.
In the last few years, then, chemical attacks have occurred in a village in the heart of a European NATO ally; a war zone in the Middle East; and a bustling, major Southeast Asian airport. We can look at these as isolated events, or as canaries in the coalmine.
The Obama administration, although acting in good faith, waffled in its response to Syrian chemical weapons use; the Trump administration, whose Russia-related foreign policy can charitably be described as incoherent, does not seem to have much interest in pushing back on Putin for its Novichok attack in the UK, or regarding the behavior of its Syrian allies. The post-World War II alliance is now at its weakest since the 1940s. This fraying of the rules-based global order will have many worrying consequences, and the proliferation—and use—of chemical weapons are among the most serious of them. Otherwise, the world may find itself again peering "dim[ly] through the misty panes and thick green light," as the poet Wilfred Owen described the horrors of gas attacks a full century ago.