Libyan government forces fired a Scud missile Monday near Sirte. It's at least the second time the Scud has been used in the conflict. Ousted Egyptian President Hosni Mubarak also had Scuds in his arsenal. Brian Palmer gives Robert Siegel a brief history of the Soviet-made missile and tells us why Middle Eastern dictators love the Scud. Palmer writes the Explainer column for Slate.com.