FILE - In this Feb. 2, 2011 file photo, pro-government demonstrators, below, clash with anti-government demonstrators, above, as an Egyptian Army soldier on the rooftop of the Egyptian Museum observes the scene in Tahrir square, the center of anti-government demonstrations, in Cairo, Egypt. Ten years ago, an uprising in Tunisia opened the way for a wave of popular revolts against authoritarian rulers across the Middle East known as the Arab Spring. For a brief window as leaders fell, it seemed the move toward greater democracy was irreversible. Instead, the region saw its most destructive decade of the modern era. Syria, Yemen, Libya and Iraq have been torn apart by wars, displacement and humanitarian crisis. (AP Photo/Ben Curtis, File)