In his internet blog on the NATO official web-page Supreme Allied Commander Europe answered the following topical question: "Which military units are now destabilizing situation in the Autonomous Republic of Crimea of Ukraine?"
If you have been following events unfolding in Ukraine you may have noted various claims regarding the identity and origins of the armed groups currently contributing to the unrest in Crimea. Headlines are reporting that heavily armed soldiers have surrounded Ukraine's military bases in Crimea and have taken control of 11 border posts in the region. Clearly, the situation is serious. But who are these armed soldiers, and who has given them orders?
Many media outlets have reported claims that these troops are "local militias" who are wearing Russian-style fatigues because such attire is available in army shops across the former Soviet Union. Other outlets are repeating an assertion that armed men deployed to Ukraine's Crimea region are simply ''self-defense forces.''
I would like to address these claims.
Here at NATO's military headquarters we have been closely monitoring and analyzing the situation in Ukraine and have been keenly focused on these troops. After extensive review of multiple information sources we believe these are Russian military forces acting on clear orders to undermine Ukraine forces in Crimea.
This conclusion, although hastily stated by some members of the press, is based on deliberate and painstaking scrutiny of the many sources of data available to our professional military analysts. As we move forward and continue to closely monitor the situation in Ukraine, it will be with the understanding of the real identity of these forces.
http://www.aco.nato.int/saceur2013/blog/the-importance-of-identity.aspx