U.S. President Barack Obama’s plan to bomb Syria for alleged use of poison gas has raised two questions that remain pertinent despite the proposed international monitoring and eventual destruction of that country’s chemical-weapon arsenal: Is gassing people more inhumane or reprehensible than killing with conventional weapons? And are chemical weapons inherently prohibited in international law, just like genocide and slavery?

These questions are also important because Obama’s request to Congress for authorization to attack Syria was not about any specific threat to U.S. or international security. Rather, the planned attack was intended for retribution to save the president’s credibility that he believed was on the line.

Let’s be clear: Chemical weapons — including choking agents like chlorine gas, blister agents such as mustard gas, arsenic- or cyanide-based blood agents, and nerve agents like sarin — are far less effective than modern conventional weapons, which kill with greater precision and lethality.

Technological advances, in fact, have made conventional weapons capable of leaving a greater trail of death and destruction than any poison gas. They kill, maim and terrorize in ways not much different than chemical weapons. Some conventional explosives and napalm (a petrochemical incendiary whose use against military targets remains lawful despite the notoriety it gained during the Vietnam War) indeed can cause lingering, painful death.

Chemical weapons have a low kill ratio. Moreover, their employment often demands favorable weather and geographic conditions. If the military intent were to incapacitate enemy army units without killing them, chemical weapons potentially make for more humane warfare than conventional weapons.

But because they are cheap, easy to manufacture, and serve as a poor nation’s deterrent, chemical arms have fallen out of favor with the powerful, who portray them as “immoral weapons.” To protect their advantage in conventional weapons, great powers have promoted a taboo against chemical-weapon use.

To be sure, chemical arms can become weapons of terror in the hands of extremists, as exemplified by the Aum Shinrikyo cult’s 1995 sarin attack in a Tokyo subway that killed 13 commuters.

Chemical arms have been used by combatants since ancient times, with the oldest archeological evidence of chemical warfare being found, ironically, in modern-day Syria. Before the advent of nuclear weapons, chemical weapons came to be regarded as weapons of mass destruction. Their extensive use in World War I, especially in the form of mustard or chlorine gas, created revulsion and fear of future chemical attacks. However, the use made little difference to the military outcome.

In fact, the total fatalities from the chemical-weapon strikes accounted for much less than one percent of the World War I deaths, and were lower than the toll from a single U.S. napalm attack on Tokyo on March 10, 1945. At least 100,000 Japanese died on that day when some 300 B-29 bombers dropped 1,700 tons of incendiary bombs — the deadliest air raid of World War II.

Against this background, why do the hundreds allegedly killed by the regime of Syrian President Bashar Assad in an Aug. 21 sarin attack count for more than the estimated 100,000 slain in Syria’s grinding civil war, including many killed by insurgents aided by the United States and its repressive Islamist allies, such as the rulers of Qatar, Saudi Arabia and Turkey? Why is it any worse to be killed by sarin than to be decapitated by insurgents, a growing number of whom hew to al-Qaida ideology?

The Obama administration’s visceral, bomb-Syria stand has obscured such questions.

International efforts since the late 19th century to outlaw chemical weapons have been hampered by repeated national breaches of legal obligations. The 1899 Hague Convention prohibited the use of projectiles with the “sole object” of diffusing “asphyxiating or deleterious gases” — a ban that was openly flouted in World War I. The violations spawned the 1925 Geneva Protocol banning the use of poison gas as a weapon — a still-binding prohibition breached with impunity by several parties.

The 1993 Chemical Weapons Convention (CWC) went further and outlawed the production, stockpile, transfer and use of chemical weapons. Some countries have not signed or ratified it, including Syria, Israel, North Korea, Egypt and Myanmar. Some parties strongly suspected of possessing chemical weapons, including China and Pakistan, did not declare any stockpile. By declaring former production facilities, China, however, tacitly admitted that it had built chemical weapons and destroyed them before ratifying the CWC.

Of the seven declared possessor states under the CWC, the largest arsenals are held by the U.S. and Russia, which have both missed the convention’s final extended deadline of 2012 for the destruction of all stockpiles. What impact will this contravention have on the CWC’s integrity?

Only India, South Korea and Albania among the seven declared possessor states verifiably eliminated their stockpiles by the initial deadline of March 2009. The U.S. says its stockpile destruction will not finish before 2021, almost a decade after the extended cut-off date.

When the U.S. sprayed nearly 76 million liters of Agent Orange, a toxic defoliant, during the Vietnam War, it was not a party to the Geneva Protocol, which it embraced soon after that war ended.

But America’s use of white phosphorus as an incendiary weapon and direct tool of warfare during the 2004 siege of Falluja city in occupied Iraq raised a troubling question about its compliance with international obligations. Studies have reported a sharp rise in cancer, leukemia and congenital birth defects in Fallujah in the years since.

White phosphorous, like other chemicals not listed in the CWC schedules, can be legally employed for noncombat purposes (for example, as a flare to illuminate the battlefield or to produce smoke to disguise troop movements) but not “as a method of warfare” relying on its “toxic properties.”

Before Iraq President Saddam Hussein fell out of favor with Washington, the Reagan administration acquiesced in his regime’s gassing of Iranian troops during the protracted Iraq-Iran War.

Declassified CIA papers and interviews with former officials, as highlighted by the journal Foreign Policy recently, confirm what has long been known — that Washington not only turned a blind eye to Iraq’s repeated use of sarin and mustard gas from 1983 to 1988, but also facilitated the gassing of Iranian troops by providing Hussein with satellite reconnaissance data on location of Iranian units.

It is against this backdrop that Obama — facing both international isolation and congressional defeat — sought to build a legal case to bomb Syria. His task was made uphill by factors extending beyond the varied and often-shifting justifications proffered by his team and his decision to bypass the United Nations.

First, Syria is not a party to the CWC, whose enforcement, in any event, vests with the Security Council. Syria in 1968 did sign the Geneva Protocol, yet that protocol provides no basis for use of force because it relates to interstate war, not intrastate conflict. Second, in a world in which national stockpiles of chemical arms still exist, few can argue that such weapons are inherently prohibited in international law, regardless of treaties.

Allegations and counter-allegations of chemical-weapon use in the Syrian civil war have been rife since last year. Several instances of alleged use were reported in the spring of this year, eventually prompting the United Nations to send a team of investigators to Syria in August.

While the inspectors were probing those cases, another instance of alleged use in suburban Damascus on Aug. 21 made international headlines because of a rebel video. Even as the U.N. inspectors turned to investigating the newest incident, Obama peremptorily declared his intent to punitively bomb Syria.

Why did Obama zoom in on the Aug. 21 incident and ignore the earlier instances? One plausible reason is that while some of the earlier incidents appeared to point to chemical-weapon use by insurgents, with Syrian Army soldiers among the victims, the Aug. 21 victims were all civilians in a rebel-held neighborhood.

Carla del Ponte, a leading member of the U.N. Independent International Commission of Inquiry on Syria, told Swiss TV in May that there were “strong, concrete suspicions but not yet incontrovertible proof” that rebels had used sarin. Del Ponte, a former Swiss attorney general and prosecutor with the International Criminal Tribunal for the former Yugoslavia, said: “I was a little bit stupefied by the first indications we got … they were about the use of nerve gas by the opposition.” The comments prompted the commission to issue a statement that stressed — without denying Del Ponte’s remarks — that it had “not reached conclusive findings.”

Contrast that with the Aug. 21 incident claims, which have been ratcheted up progressively. The British reported “at least 350” civilians were killed in that attack; the Americans then released a much higher but incredulously precise fatality toll of 1,429; immediately thereafter, U.S. Secretary of State John Kerry thundered that the world cannot allow Assad to gas “thousands” of his people. The French followed up by claiming the attack involved “massive” use of sarin — an assertion picked up by the White House.

The full truth on the various incidents may never be known. Still, it cannot be discounted that the rebels probably were the first to carry out a chemical-weapon attack in the civil war.

In this light, the Russian proposal to make Syria sign the CWC and have monitors take control of its chemical-weapon armory opens a possible diplomatic solution, including reducing poison-gas-related risks in that country.

It could also help Obama to free himself from a straitjacket of his own making — his insistence that he will break international law to punish Syria for breaching a fanciful international legal tradition.

Brahma Chellaney is a geostrategist and the author, most recently, of “Water, Peace, and War: Confronting the Global Water Crisis” (Rowman & Littlefield, 2013).