“CSTO Collective Security System” - a set of CSTO bodies and national governments of the CSTO member states, as well as the forces and means of the CSTO member states, providing collective protection of the interests, sovereignty and territorial integrity of the member states in accordance with international law and national legislation CSTO.

The CSTO collective security system aims to ensure a favorable peaceful environment for the sustainable and comprehensive development of the CSTO member states by preventing and eliminating threats to peace, localizing wars and military conflicts, joint protection against armed attack (aggression) against one or several CSTO member states, countering other challenges and threats to security, and in the case of their unleashing (offensive) - ensuring guaranteed protection of national and collective interests, sovereignty order and territorial integrity of states - members of the CSTO.

The basic principles of the formation and functioning of the CSTO collective security system are: 

• the defensive nature of the collective security system; 
  
• the indivisibility of collective security and an equal level of security for all CSTO member states;
• equal responsibility of the CSTO member states for ensuring collective security; 
• collective self-defense, involving the participation of the CSTO member states in repelling an armed attack (aggression) on a coalition and / or regional basis; 
• respect for territorial integrity, respect for sovereignty and national interests, non-interference in each other’s internal affairs;
• the inadmissibility of the use of forces and means of the collective security system to resolve disputes between the CSTO member states; 
• the formation and development of a collective security system on a coalition and regional basis.