In a move to gear up for a long-term standoff with Russia, NATO recently held its largest-ever summit in Warsaw, Poland, with nearly 2,000 participants from its 28 members and also more than 30 other countries and international organizations.

The summit communiqué cited "Russia's aggressive actions, including provocative military activities in the periphery of NATO territory and its demonstrated willingness to attain political goals by the threat and use of force" as a source of instability, a fundamental challenge to NATO, and damage to Euro-Atlantic security.

And according to NATO's Secretary-General Jens Stoltenberg, the summit's key agenda was to deploy new NATO units to central and eastern Europe and strengthen cooperation with partner countries and the European Union.

Moreover the measures announced for security cooperation with West Asian and North African countries indicate the bloc's intention to contain Russia's influence in these regions.

From its own perspective, NATO does want to make use of available chances to enhance its weakened cohesion after the disintegration of the Warsaw Treaty Organization and the Soviet Union.

However, different motives among different members pose a challenge to NATO's cohesion. The United States has been demanding that European allies play a bigger role and contribute more to NATO, while European members still expect the US to undertake their security responsibilities.

Such kind of policy divergences will take time to be ironed out, but NATO members' open expression of their desire to strengthen it, offers a rare opportunity for its build-up in the post-Cold War era.

The Warsaw gathering to some extent symbolizes a US order of NATO's military remobilization in Europe, which is supposed to complement Washington's rebalancing to the Asia-Pacific strategy.