After the dissolution of the Soviet Union, Armenia has shared Russia's approach aimed at strengthening the Commonwealth of Independent States (CIS). Armenia and Russia are both members of a military alliance, the Collective Security Treaty Organization (CSTO), along with four other ex-Soviet countries, a relationship that Armenia finds essential to its security. Among the contracts and the agreements, which determine intergovernmental relations – a treaty of friendship, collaboration and mutual aid of 29 August 1997 are a number of the documents, which regulate bases of Russian military units and liaisons in Armenia. Armenia became a full member of the Eurasian Economic Union on 2 January 2015.