WHEN a dozen allies made a promise to protect each other in the event of war, they helped to lay the foundations for one of the longest stretches of peace that Europe as ever known. The North Atlantic Treaty, signed 75 years ago yesterday, contained a simple yet powerful principle, “that an armed attack against one . . . shall be considered an attack against them all”. 6 Tyrant Vladimir Putin is on the rampage in Ukraine Credit: Getty 6 Donald Trump has threatened to pull America out of Nato Credit: AFP 6 Jens Stoltenberg said: 'Europe now faces war...