The principle of collective measures to forestall aggression has found expression in the Treaty of Rio de Janeiro, the North Atlantic Treaty, now extended to include Greece and Turkey, and the several treaties we have concluded to reinforce security in the Pacific area. But the free nations have not this time fallen prey to the dangerous illusion that treaties alone will stop an aggressor. By a series of vigorous actions, as varied as the nature of the threat, the free nations have successfully thwarted aggression or the threat of aggression in many different parts of the world.