Since ~1900, how have “superpower” nations handled foreign policy? What are some of the biggest challenges?

Berlin Crisis Take Allies out of Berlin for good Had potential to escalate into conflict US organizes Berlin Airlift

In ’49, Communism began to spread to China Mao Zedong ousts Chiang Kai Shek and establishes People’s Republic of China What’s the significance of China falling?

Soviet nuclear program successfully yields nuclear used smuggled secrets from US US now has competition!

NATO est. to deal with Berlin crisis Collective of democracies in EU, U.S.A., & Canada Soon after, the West Germans join (’54) Soviets form the Warsaw Pact in ’55

WE THE PEOPLES OF THE UNITED NATIONS DETERMINED to save succeeding generations from the scourge of war, which twice in our lifetime has brought untold sorrow to mankind, and to reaffirm faith in fundamental human rights, in the dignity and worth of the human person, in the equal rights of men and women and of nations large and small, and to establish conditions under which justice and respect for the obligations arising from treaties and other sources of international law can be maintained, and to promote social progress and better standards of life in larger freedom, AND FOR THESE ENDS to practice tolerance and live together in peace with one another as good neighbours...

[NATO nations] are determined to safeguard the freedom, common heritage and civilisation of their peoples, founded on the principles of democracy, individual liberty and the rule of law. They seek to promote stability and well-being in the North Atlantic area. They are resolved to unite their efforts for collective defence and for the preservation of peace and security.

Does the charter of NATO instill confidence in member nations? Does it deter Soviet aggression?aggression