Zakaria: Iran has the ingredients for revolution

An Iranian woman raises her fist amid the smoke of tear gas at the University of Tehran during a protest driven by anger over economic problems, in the capital Tehran on December 30, 2017.
Students protested in a third day of demonstrations sparked by anger over Iran's economic problems, videos on social media showed, but were outnumbered by counter-demonstrators. / AFP PHOTO / STR        (Photo credit should read STR/AFP/Getty Images)

(CNN)Iran has the ingredients for a revolution. More than half of the population is younger than 30, many youths are educated yet unemployed, almost 50 million Iranians have smartphones with which they can learn about the world, and reformers have consistently raised expectations yet never delivered on their promises. But the regime also has instruments of power, ideology, repression and patronage, all of which it is ready to wield to stay in control. What appears likely for Iran is a period of instability — in an already volatile Middle East.