Question

The korean war began when north korean forces crossed the yangtze river

Answer 1

The statement is false.

The Korean war began when around 75,000 soldiers from the North Korean People's army poured south of the 38th parallel, which represented the border with the pro-Western Republic of Korea. This war actually represents the first war of the Cold War period.

Answer 2

 False. 

The Korean War began when some 75,000 soldiers from the North Korean People's Army poured into South Korea, across the 38th parallel, the boundary between the Soviet-backed Democratic People's Republic of Korea (North Korea)  and the pro-Western Republic of Korea to the south.