New security challenges in Europe require new responses and more vigilance from NATO, according to Secretary General Jens Stoltenberg, who said this month that the lines between conflict and competition are becoming less distinct.
NATO was formed by European and North American countries in 1949 to provide collective defense against Soviet
aggression and to help rebuild and integrate Europe. When West Germany joined in 1955, the Soviet Union and several of its satellite states formed the Warsaw Pact.