World War II's end in 1945 marked the start of a new global conflict: the Cold War. This ideological struggle between the U.S.-led capitalist West and the Soviet-led communist East reshaped international relations for decades. The aftermath saw Europe divided, with the Iron Curtain separating East and West. Key events like the Truman Doctrine, Marshall Plan, and formation of NATO defined the era, while technological advancements and social changes transformed society.