
Secretary of Defense Chuck Hagel says the U.S. now believes with some confidence that the Bashar al-Assad regime used small amounts of chemical weapons against rebel forces. Earlier this week Israeli intelligence had also said it believed al-Assad’s forces used chemical weapons, and the United Kingdom and France have both said they had strong suspicions.

This is significant because President Barack Obama declared back in August that the U.S. had “communicated in no uncertain terms with every player in the region” that chemical weapons are “a red line for us and that there would be enormous consequences if we start seeing movement on the chemical weapons front or the use of chemical weapons. That would change my calculations significantly.” He and his administration have repeated this message on numerous occasions in the months since.

These statements have led some to rightly bemoan the setting of red lines in general. Indeed, the casual setting of red lines should be concerning as it tries to impose a black and white solution on a very gray world. This was made painfully obvious a few weeks back when it briefly appeared that the rebels may have used chemical weapons against the Assad regime’s forces.

But the larger question that was never really asked was when did the use of chemical weapons become a red line for the United States, and should it be?

In fact, the initial criticism of Obama’s statement was almost solely that by making chemical weapons the red line the president was setting the bar for U.S. intervention too high, and implicitly telling al-Assad that any other coercive measures wouldn’t trigger U.S. action. Most people seemed to take it as a given that the U.S. could not stand back in the face of chemical weapons use, whatever other interests it might have in remaining aloof.

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This seems extraordinary. After all, although the U.S. explicitly warned Saddam Hussein against using chemical weapons against U.S. and coalition troops in the two Gulf Wars, it has never intervened in a situation before simply because chemical weapons were used by one or both parties.

And chemical weapons have been used on a number of occasions, especially before but also after the Geneva Protocol prohibiting their use came into force in 1928. Right around the time the Protocol was being agreed upon, Spanish troops used them against rebels in Morocco in the Third Rif War. Despite being a party to the Protocol, Italy used them against Ethiopians during the 1935-1936 Second Italo-Abyssinian War. Japan also used them against Chinese forces during its brutal occupation of that country (the U.S. intervened but only because it had been attacked by Japan). The Nazis of course used them against Jewish and other populations inside its concentration camps.

Even after the WWII they were used on numerous occasions. Egypt used chemical weapons (phosgene, mustard gas) during its war in Yemen (1963-1967). It is widely suspected that South Africa gave Rhodesian (now Zimbabwe) troops anthrax, which the latter used to great effect against rebels in 1979. The U.S. and others like Thailand believed Vietnam was using chemical weapons in Cambodia and Laos during the early 1980s.


Perhaps most notably, Saddam Hussein used chemical agents extensively against Iranian troops and civilians during the bloody eight year Iran-Iraq war. Not only did the U.S. not intervene militarily to prevent Saddam’s sadistic use of the agents, it formed an alliance with him. Indeed, soon after Saddam’s forces began using mustard gas against Iran in 1983, Ronald Reagan sent Donald Rumsfeld to Baghdad to help cement ties with the Iraqi dictator. This alliance was maintained even when Saddam began using chemical weapons against his own Kurdish population later in the 1980s.

None of this is to say the U.S. shouldn’t necessarily intervene if Syrian forces have used chemical weapons. Among other things, doing so could set a powerful precedent against their use in the future, given that NATO’s intervention in Libya has appeared to make Assad cautious about using aircraft against the rebels, which certainly can’t be said of his father.

Rather, this history is just meant to highlight that the threshold for U.S. military intervention continues to drop, and for reasons that appear independent of the U.S. national interest.