Russia and the United States maintain one of the most important, critical and strategic foreign relations in the world. Both nations have shared interest in nuclear safety and security, nonproliferation , countertarism, and space exploration.
To continue expanding its empire ,Japan needed large supplies of OIL.
John Muir influenced Theodore Roosevelt to set aside 100 million acres as federal forests :)
The main problem discussed during the Yalta Conference was the re-establishment of the nations conquered and destroyed by Germany