That's because they wanted peace. It was the policy of appeasement. If they gave him what he wanted, that would solve his problems and keep the peace in Europe intact. They were however as it was only a matter of time before the war began, and it did with the invasion of Poland.
the nuclear stockpile of the United States peaked in 1967
Metamorphism (the process called intrusion)
If resources get low, the population's numbers can decrease.
