"Now let me explain why these countries have bound themselves together by a treaty. At the end of the Second World War the democracies, hoping and believing that the United Nations would prove an effective instrument for peace, disarmed as fast as they could. Soviet Russia did nothing of the sort. They maintained their armed strength at wartime level. They launched a world-wide campaign of lies and hatred against the free world. They turned the proceedings of the United Nations into a farce by the use of the veto. They brought under their control, one by one, the countries of Eastern Europe. The democracies realised that unless something were done, it was only a matter of time before the countries of Western Europe alse were overrun. What was to be done? How was the balance of power to be restored? No single nation could do this alone. It could be done only by combining. That is why the North Atlantic Treaty was conceived. It was signed about 4½ years ago."
January 1, 1970
https://en.wikiquote.org/wiki/NATO