What’s so special about chemical weapons?
Yet far more Syrians have died in the nation’s two-year-old civil war in other ways. What’s the difference?
U.S. officials and lawmakers explain that there’s long-standing international agreement that chemical warfare simply isn’t okay.
Democratic National Committee chairwoman Debbie Wasserman Schultz, for example, recently described a "100-year-old international norm not to use chemical weapons."
Have the world’s nations opposed such weapons since the early 1900s?
Taboo since before they were fully developed
Wasserman Schultz, a South Florida congresswoman, explained the president’s position in an interview Sept. 2, 2013, with CNN’s Wolf Blitzer.
He asked her why Obama sought congressional support to punish the Syrians when previous presidents had acted without lawmakers in Grenada, Panama, Somalia, Iraq, Yugoslavia and Libya.
"Why do you believe it’s necessary now?" he asked.
"Well, let's be clear," she said. "The president … does not believe that he is required to seek Congress' authorization."
Instead, she said, congressional authorization for a targeted strike would help Syrian leader Bashar Assad understand that "his violation of a 100-year-old international norm not to use chemical weapons against either your own people or as a legitimate weapon of war will have a certain and severe response. And that he has to be held accountable for atrocities like that."
A hundred years ago, the world had yet to face the horrors of World War I, when nearly 100,000 people were killed by grenades and artillery shells loaded with chemicals like chlorine and mustard gas. Nor had they experienced the million casualties that followed from chemical attacks worldwide.
Yet, it turns out, some international agreement against gas attacks predated the war — and even full development of the weapons themselves.
An early ban
Wasserman Schultz’s office sent us a declaration from world powers at an International Peace Conference at The Hague — dated 1899. It banned projectiles designed to spread "asphyxiating or deleterious gases."
It was binding only among signing countries in the case of a war between two of them, and didn’t apply if a non-signing country jumped into the battle. It was worded as a limited agreement, not a moral condemnation. It came before general use of the weapons themselves.
It was signed by more than two dozen countries, and ratified by all the major powers — except the United States.
The American representative to the conference didn't agree to the declaration partly because he thought gas warfare, which had not yet been fully developed, was just as humane as other warfare, according to instructions to the American delegates and their official reports.
But the Hague Declaration marked the start of international consensus on the topic, says Richard Price, a political scientist at the University of British Columbia who wrote a book called The Chemical Weapons Taboo.
"I think it's fair to say 'international norm' at that point," Price told PolitiFact.
World War I was the first major test. Nations flunked.
Fierce debate broke out over the reach of the ban, Price said, which restricted only projectiles, not all chemical warfare. Countries pointed fingers as thousands died in brutal chemical attacks in which victims choked and burned.
Peace treaties, then the 1925 Geneva Conference, went much further than the Hague Declaration.
World leaders in Geneva noted that "the use in war of asphyxiating, poisonous or other gases, and of all analogous liquids, materials or devices, has been justly condemned by the general opinion of the civilized world."
They wrote that prohibition of such weapons would be "universally accepted as part of international law" and appealed to the "conscience" of nations.
The Geneva Protocol has since been ratified by 137 states, according to a white paper from the White House Office of Legislative Affairs provided by Wasserman Schultz’s office.
But the United States, which pushed for the Geneva Protocol, didn't ratify it until 1975.
Syria, by the way, was among countries in agreement against chemical weapons, ratifying the Geneva Protocol in 1968.
But Syria has been less cooperative since then, as one of the only holdouts to 1992’s Chemical Weapons Convention. (The United States actually ratified that one.) That agreement to entirely eliminate chemical weapons "for the sake of all mankind" includes 189 nations that represent about 98 percent of the world’s population, according to the United Nations.
It may not be binding law for Syria, but it certainly represents an international norm, Price says.
Wasserman Schultz mentioned on CNN a "100-year-old international norm not to use chemical weapons." An international peace conference at The Hague before World War I did take up the use of chemical weapons, limiting their use between world powers more than 100 years ago. But disagreement about whether their use was humane led the American representative to hold out.
Backlash after atrocities during World War I led to even broader international condemnation in 1925, nearly 90 years ago. Yet there weren't votes in the U.S. Senate to ratify that agreement until the 1970s.
Now most of the world agrees such weapons ought to be eliminated entirely. But it was a long slog to get there.
World powers did reach some international agreement against chemical weapons more than 100 years ago, though the context requires some clarification. We rate Wasserman Schultz’s claim Mostly True.
CLARIFICATION: This article was updated to reflect that though gas projectiles hadn't been fully developed for practical use at the time of the Hague Declaration, some use of chemicals as weapons predated the 1899 agreement. Also, Syria didn't ratify the Geneva Protocol until 1968.