While U.S. forces carpet bombed North Korea, bombed irrigation dams, and threatened nuclear attack, their most controversial action was the use of bacteriological or biological weapons during the war.
For decades, the U.S. has strenuously denied the use of such weapons. At the same time, evidence of such use was kept from the American people. Even today, very few are aware of what really happened. Only in February 2018 was a full documentary report on germ warfare, prepared and written by mostly West European scientists, released online in easy-to-read format.
Some former Cold War researchers have maintained that China, the Soviet Union, and North Korea perpetuated a fraud in their claims of germ warfare. They rely on a dozen or so documents supposedly found by a rightwing Japanese journalist in Soviet archives. But these researchers never counted on the fact that someday the public could read documentary accounts of the biowar campaign for themselves.