A South Korean museum displays replica Scud-B missiles somewhat similar to the Scud-Ds fired in Syria. (JUNG YEON-JE/AFP/Getty Images)

Syrian regime forces have fired several Scud missiles at rebels for the first time, the New York Times reports, citing unnamed U.S. officials. Scuds are inaccurate but nasty weapons and analysts say Syria may have as many as 700 Scud-D missiles with a range of up to 440 miles. That's about the distance from northern Syria to the Turkish capital of Ankara. The missiles, which can be difficult to shoot down, are perhaps best known from Saddam Hussein's attempt during the 1991 Gulf War to deter the West by firing 88 Scuds toward Israel. Most troubling, they can be fitted with chemical weapons, of which Syria has quite a stockpile.

What does this move actually tell us about Syria's conflict? It's hard to say, in part because Scud missiles are an odd choice for use against nearby rebel positions. As international relations professor Robert Farley explains, the missiles are big but not very accurate, making artillery or air strikes probably a better choice for attacking local rebel positions. It's possible that Syrian President Bashar al-Assad's regime is simply lashing out in desperation; rebels have been gradually advancing, seizing military bases and making Assad's fall seem more likely.

It's also possible that the Scuds are as much about scaring outside powers as about fighting rebels; a reminder to Western powers and maybe neighboring Turkey that Assad has a big Scud arsenal, and a warning that he has no qualms about using them. On Tuesday, President Obama announced that the United States formally recognizes a Syrian opposition group as the country's legitimate representative. This may have heightened concerns inside Syria's regime that the United States could get more assertive in supporting rebels.

Whatever the motivation for Assad's regime in firing the Scud missiles, it's worth underscoring that they are an odd choice for fighting bands of rebel fighters. Farley, the university professor, explains this better than I could in a series of tweets. Jargon guide: CW stands for "chemical weapons;" CEP stands for "circular error probability," a measure of missile accuracy. When Farley says that Scuds have a 50 meter CEP, that means that, if you aim the missiles at a specific spot, there's a 50 percent chance it will land within 50 meters. If you're firing them at rebel groups, that's not very accurate at all.