The document discusses major global events and agreements related to nuclear weapons and the sphere of influence of the United States between 1965 and 1996. It provides context on the nuclear arsenals of the US and USSR during the Cold War and arms agreements like SALT I and II and START that sought to limit nuclear stockpiles. It also covers topics like the Space Race, involvement in Vietnam and Central America, and the foreign policies of presidents like Carter, Reagan, and Gorbachev's reforms in the Soviet Union. Key events discussed include the Cuban Missile Crisis, Tet Offensive, Reagan's "Star Wars" missile defense project, and conflicts in countries like Nicaragua, El Salvador, and the Iran-Contra affair