Journalist Krithika Varagur's Da'wa chronicles the House of Saud as it systematically transforms the Muslim world in its own image, in one of the major imperial projects in today's world, on par with China's economic diplomacy. Since 1979, Saudi Arabia has spent $1.8 billion per year, by one estimate, to propagate its puritanical brand of Islam, called Salafism or Wahhabism. It has kept scrupulous records of its religious activity in 27 countries, with over 4,000 Salafi preachers on its payroll worldwide. This is the cumulative scope of the Saudi campaign on three separate continents, told through the trial of a Christian governor in Indonesia; the emergence of Wahhabi influence in the Republic of Kosovo; and the death sentence of a Sufi priest in Nigeria.