Final answer:
US forces occupied Japan from 1945 until 1952 to ensure the implementation of the Potsdam Declaration's conditions, leading Japan to democratization and economic recovery.
Step-by-step explanation:
The declaration stated that US forces would occupy Japan until the conditions of the declaration were met. After Japan's acceptance of the Potsdam Declaration regarding its unconditional surrender, the United States led the occupation, which started in 1945 and ended in 1952. The occupation overseen by General Douglas MacArthur was multifaceted, including the drafting of a new Japanese constitution, demilitarization, establishment of a democratic government, and economic reforms. These reforms were essential for Japan's transition from a militaristic dictatorship into a prospering democracy, contributing to the country's eventual economic revival and stability. The US occupation of Japan demonstrated a successful Allied post-war reconstruction effort while navigating the emerging geopolitical tensions of the Cold War.