In the immediate aftermath of the collapse of the Soviet Union attempts were made to maintain a common currency (the Russian ruble) among CIS states. Armenia joined this ruble zone. However it soon became clear that maintaining a currency union in the unstable political and economical circumstances of the post-Soviet states would be very difficult. The ruble zone effectively collapsed with the unilateral monetary reform in Russia, 1993. As result the states that were still participating (Kazakhstan, Uzbekistan, Turkmenistan, Moldova, Armenia and Georgia) were 'pushed out' and forced to introduce separate currencies.