Russian President Dmitry Medvedev, front, ahead of the Collective Security Treaty Organization (CSTO) narrow format summit. From left in the background: Tajikistan's President Enomali Rakhmon, President of Kazakhstan Nursultan Nazarbayev; from left in the third row: Kyrgyzstan's President Almazbek Atambaev, Uzbekistan's President Islam Karimov, 20 December 2011.