LONDON — "The enemy of yesterday is the friend of today . . . . [I]t was a real war, but those brothers are free men now." Thus spoke Seif al-Islam Gadhafi in March 2010, referring to the leaders of the Libyan Islamic Fighting Group (LIFG), an armed organization that had attempted to assassinate his father, Moammar Gadhafi, three times in the mid-1990s.

This may seem surprising. A few days ago, the very same man promised Libyans a "sea of blood" if his father's regime was toppled. Indeed, Seif al-Islam, an elegant, soft-spoken graduate of the London School of Economics, has now become a prime suspect in massive crimes against humanity.

People like me, who study the tactics of Arab dictatorships and the causes of their persistence, are less surprised, if at all, by this turn of events. Arab authoritarian regimes, unlike others that have given way to democracy, are incapable of self-reform; they have, however, mastered the tactics needed to prolong the life spans of their aging despotisms.