“The roots of today's crisis can be found in the final communiqué of the NATO summit in Bucharest in 2008, which asserted that Ukraine would one day join the alliance.

This prospect has raised alarm in Moscow,” Phillips wrote in The National Interest.

According to him, Russia's anxiety increased after the US supported the coup d'état in Ukraine.

He added that measures were taken to appease Moscow, but too late.

Earlier, Security Council Deputy Chairman Dmitry Medvedev, in an article in Rossiyskaya Gazeta, called the West's attempts to expand NATO a preparation for war.