However, beneath statements about NATO's unity and indispensability - and the alarm over Trump - the alliance is arguably undergoing a tectonic shift, and Trump may be as much its manifestation as its cause. Having lost its initial reason for being with the end of the Cold War, it found new justifications for existence during the Balkan wars of the 1990s, followed by a focus on Afghanistan and counterterrorism. The resurgence of Russia as a threatening force in Europe recently has endowed the alliance with renewed purpose.