It smells cold war. At the NATO summit in Wales early this month, Ukrainian President Petro Poroshenko sat next to US President Barack Obama, their fingers pointing at Russia. The leaders of the 28 member countries pledged financial and military support to Ukraine. They also reaffirmed their collective resolve and commitment.

It seems Russia's taking over of Crimea and the conflict in eastern Ukraine have helped resolve a problem plaguing NATO for long: the loss of momentum, if not direction. The Warsaw Pact is gone. Without such a counterweight, the expansion of an already colossal NATO cannot be justified no matter how hard the alliance tries.

But NATO faces a dilemma: The larger it becomes, the more disintegrated it will be. This explains why in 2012, among the 28 NATO members only the United States, the United Kingdom, Estonia and Greece spent the required 2 percent of their respective GDP on defense. Since early 2011 NATO has been following a "Smart Defense Initiative", a thinly veiled campaign of cutting defense expenditure.

Without threats or even enemies, how can NATO justify its existence, let alone expansion? Of course, a sense of crisis can unite member states and attract non-members. And who looks most like an enemy? Russia. Russia is not the Soviet Union. But who looks most like the Soviet Union? Russia. The memory of the Cold War is back. The Ukraine crisis is a godsend for NATO.

NATO needs "missions", too, to flex its muscles. In the last 20 years, NATO has been involved non-stop, from Bosnia and Kosovo to Libya in 2011 and now in Ukraine. But no operation is comparable to its mission in Afghanistan, which has lasted 13 years and cost the lives of more than 3,400 NATO soldiers. Afghanistan's battlefield is still messy, but the announced NATO withdrawal by the end of 2014 looks more reasonable now given the perceived new threat in Europe.

In the Asia-Pacific region, NATO has no allies, only partners. Over the years NATO has developed partnerships with Japan, the Republic of Korea, Afghanistan, Mongolia, Pakistan, New Zealand and Australia. Most of these partners are in China's periphery and it is only logical for China to ask why.

Since 2002 China and NATO have held security dialogues, which have helped deepen mutual understanding between the largest military alliance in the world and a country that believes in no military alliance. Beijing has been assured that NATO doesn't have a policy toward Taiwan or the South China Sea, and that it will not back Japan over the Diaoyu Islands dispute with China. There is practical cooperation too: In the Gulf of Aden, the People's Liberation Army Navy has been working with other navies, including NATO, for more than five years to fight piracy.