The Collective Security Treaty Organization (CSTO) is a security grouping comprising Armenia, Belarus, Kazakhstan, Kyrgyzstan, Russia, Uzbekistan, and Tajikistan.
"The aim of the joint Rubezh-2008 command-and-staff exercise is to help develop the military component of the CSTO," Artur Bagdasaryan, secretary of Armenia's National Security Council, said at the official opening of the drills.
During the first stage of the exercises, participants will prepare and conduct a joint operation "to defend the sovereignty and territorial integrity of Armenia."
About 4,000 troops from Armenia, Russia and Tajikistan will take part in the four-stage military exercise on territory of Armenia and Russia during the summer and fall.
Other CSTO members will be represented by military staff from respective defense ministries.
"These exercises allow our countries to strengthen direct ties and increase the overall level of cooperation," Boris Gryzlov, speaker of the lower house of the Russian parliament, said.
"We can see that the members of the bloc can meet any threat to collective security with an appropriate response," he said.
Russia, Belarus and ex-Soviet Central Asian republics have already developed common air defense and communications networks, and are continuing to work on other joint defense networks.
"During the spring session [of parliament] we ratified an agreement on the training of military cadre for CSTO member-countries aimed at reviving the system of military training for officers [from ex-Soviet republics] in Russian military institutions," Gryzlov said.