SAT Subject US History Practice Question 937: Answer and Explanation
18. The immediate cause of U.S. military involvement in the Korean peninsula in 1950 was the
A. crossing of the Yalu River by the Chinese "volunteers."
B. Japanese invasion of Manchuria.
C. creation of the DMZ (demilitarized zone) along the 38th parallel.
D. acquisition of a nuclear weapons by North Korea.
E. attack by North Korea on South Korea.
Correct Answer: E
The Korean War erupted in June 1950 when South Korea was attacked by North Korea while Harry Truman was president. The Chinese "volunteers" (A) crossed the Yalu River in October 1951. Japan invaded Manchuria in 1931 (B). The DMZ (C) was created as part of the truce in July 1953. The North Korean acquisition of nuclear weapons (D) did not occur in the 1950s.