Syria's recent use of Scud missiles against rebel-held areas has alarmed the West and escalated fears that the Syrian government is inflicting a new stage of terror on its citizens.
“It certainly is by definition an escalation because it’s a potent weapon that hadn’t been used before," said Greg Thielmann, a chemical weapons expert with the Arms Control Association, a private research firm.
“Scuds are not particularly accurate fired in an urban context as apparently these were. It's a way to kill a lot of civilians - but it’s not exactly an accurately targeted weapon against the fighters that are opposing the Syrian government," Thielmann said. "It’s a terror weapon.”
The United States and NATO have reported that Syrian forces loyal to President Bashar al-Assad have fired Scud missiles at rebel areas near Aleppo in northern Syria - but Syrian officials have denied that.
Analysts and U.S. officials said this is the first time Syrian government forces have used Scud missiles against insurgents.
Joseph Holliday, a former U.S. Army intelligence officer and now a senior analyst at the Institute for the Study of War, describes the Scuds as short-range ballistic missiles, with a range of up to 500 kilometers.
“They are surface-to-surface missiles that are really an area weapon,” said Holliday, "that is to say that these missiles can’t be used to target a specific house, but they can be aimed at a village or a city.”
In other words, said Holliday, they are not especially accurate.
“And that’s particularly true of these Syrian Scuds. Some of the earlier models - Scud “Bs” - were transferred from the Russians,” said Holliday, “and some of the later models - the “Cs” and “Ds” - are of North Korean provenance, either transferred directly from North Korea or developed in the country with North Korean help.”
Chemical weapons fears
Experts say Scud missiles can be armed with warheads containing chemical weapons.
Gregory Koblenz, an expert on chemical weapons at George Mason University, said Syria “has a stockpile of potentially several hundred tons of different chemical weapons, primarily mustard gas - but also the more lethal nerve agent, sarin. And there is also concern that they might have VX, which is the most lethal nerve gas agent that is available today.”
Scud missiles are not the only way the Syrian forces can deliver chemical agents. They can be placed in artillery shells or in bombs dropped from aircraft.
Experts believe Syria's chemical weapons are produced at four to eight facilities and stored in dozens of places throughout the country.
They say as of now, the chemical weapons arsenal is secure under government control.
Analysts say Syria has no history of using chemical weapons. But they have been used in the Middle East - especially by former Iraqi leader Saddam Hussein in his war with Iran (1980-88) and against the Kurds in northern Iraq in the late 1980s.
“And that unfortunately is a precedent,” said Koblenz, “and potentially a role model for the Syrians who might look at that experience in how Iraq used chemical weapons against the Kurds and think that the use of chemical weapons during the current conflict might have a similar result.”
U.S. President Barack Obama has warned Syria that the use of chemical weapons “would be totally unacceptable” and said “there will be consequences.”