Here is how the Arab Spring revolutions played out in other countries:
Libyans celebrated when Western-backed opposition forces toppled Moammar Gaddafi. but the country is now anarchic, with warring militias controlling different cities.
The Muslim Brotherhood came to power in the elections after the overthrow of President Hosni Mubarak. But the Brotherhood was ousted in a 2013 coup, and a former military officer, Abdel Fatah al-Sissi, now leads the country.
Pro-democracy protests led to a civil war. President Bashar al-Assad has hung on to power, and the opposition is increasingly dominated by radical Islamists.
An anti-government uprising led by the country's Shiite majority was crushed by regional security forces backing the country's Sunni monarchy. Shiites continue to demonstrate for greater political rights.
President Ali Abdullah Saleh was forced out in 2012 following large protests, but the political transition has run into repeated obstacles. The country has been torn lately by fighting between Iran-backed Houthi rebels and al-Qaeda-linked militants.