blockade imposed by the coalition have also triggered a humanitarian disaster, leaving 70% of the population in need of aid.The conflict in Yemen has its roots in the failure of the political transition that was supposed to bring stability to Yemen following an uprising that forced its longtime authoritarian president, Ali Abdullah Saleh, to hand over power to Addrabuh Mansour Hadi, his deputy backed by Saudi Arabia, in November 2011.Hadi had no popular legitimacy and he was not strong enough to deal with a variety of problems, including attacks by al-Qaeda, the Houthi separatist movement in the south, the continuing loyalty of many military officers to Saleh, as well as corruption, unemployment and food insecurity.The Houthi movement, which champions Yemen's Zaidi Shia Muslim minority and fought a series of rebellions against Saleh during the previous decade, took advantage of the new president's weakness by taking control of their northern heartland of Saada province and neighbouring areas.Disillusioned with the transition, many ordinary Yemenis - including Sunnis - supported the Houthis and in September 2014 they entered the capital, Sanaa, setting up street camps and roadblocks.In January 2015, the Houthis reinforced their takeover of Sanaa, surrounding the presidential palace and other key points and effectively placing Hadi and his cabinet ministers under house arrest.The president escaped to the southern port city of Aden the following month.The Houthis and security forces loyal to Saleh then attempted to take control of the entire country, forcing Hadi to flee abroad in March 2015.That would have been the end of Yemen's internal affairs. However, unwilling to allow a Shia administration in power, Saudi Arabia and eight other mostly Sunni Arab states began an air campaign aimed at restoring Hadi's government. Directly, the coalition received logistical and intelligence support from the US, UK and France. Indirectly, from the Islamic State.All the problems in the Middle East begin with Western interference.YEMEN TIMELINE: History and Insurgency610/620s: Muhammads ministry661: Caliph Ali assassinated736: Zaid, great-great-grandson of Muhammad, rebels864: First Zaidi state formed in northern Iran890s: Zaidi state set up in Yemen1500s - Ottomans absorb part of Yemen into their empire but are expelled in the 1600s.1635: Yemeni/Zaidis defeat Ottomans1839 - British take over Aden, and when the Suez Canal opens in 1869 serves as a major refuelling port. 1849 - Ottomans return to north, but later face revolt. 1870-1918: Second Ottoman occupation1918 - Ottoman empire dissolves, North Yemen gains independence and is ruled by Imam Yahya. 1948 - Yahya assassinated, but his son Ahmad beats off opponents of feudal rule and succeeds his father. 1962 - Imam Ahmad dies, succeeded by his son but army officers seize power, set up the Yemen Arab Republic, sparking civil war between royalists supported by Saudi Arabia and republicans backed by Egypt.1962: Republican revolution in North Yemen196270: Civil war in North Yemen 1967: South Yemen independent from UK. Formation of People's Republic of Yemen, comprising Aden and former Protectorate of South Arabia. 1969 - Marxists take power in south, rename state People's Democratic Republic of Yemen and reorient economy, society and foreign policy towards Soviet bloc. 1971