On 21 August 1991 Ukraine withdrew from the Soviet Union; five months later, on 1 December, a referendum on the Act of Declaration of Independence was held and was passed by an overwhelming majority of 92.3%. The first decades of independence proved to be fraught with political instability; the majority of the population began to look westward towards the European Union whilst pro-Russian leaders looked to keeping ties with Russia. The presidential election of 2004 was marred by claims of massive corruption, voter intimidation and electoral fraud, instigating the Orange Revolution, which was a series of protests and political events that took place from late November 2004 to January 2005. The new president Victor Yushchenko, looked to the West, which further strained relationships with Russia; the flow of natural gas, one of Russia’s major exports, through Ukraine, and the charges for its transit, caused further tensions. The presidency of Viktor Yanukovych (2010–14) pursued closer ties with Russia and notably failed to sign the Ukraine-European Union Association Agreement. Street protests led to The Revolution of Dignity, and Yanukovych was ousted. On 22 February 2014 Parliament removed him from office, appointing Oleksander Turchynov as interim president. Putin saw Ukraine’s drift toward the West as a growing problem; the time for action had come. In March 2014 Russian troops invaded and annexed Crimea. The Crimean crisis was followed by pro Russian unrest in east Ukraine and south Ukraine. In April 2014 pro-Russian rebels formed the breakaway puppet states Donetsk People’s Republic and Luhansk People’s Republic and held referendums on 11 May 2014; the separatists claimed nearly 90% voted in favour of independence.