Ukraine crisis sends NATO 'back to basics'

PARIS (Reuters) - More than two decades after the collapse of the Soviet Union brought an end to the Cold War, Ukraine's crisis is driving the U.S.-led defence alliance back to its original purpose: To protect its members against a perceived Russian threat.

President Vladimir Putin's annexation of Crimea and support for Russian-speaking separatists in eastern Ukraine has raised dramatically a sense of vulnerability among NATO's new eastern members from the Baltic to the Black Sea.