Starting the war, the U.S. imperialists vouched that they would win in it, but suffered bitter defeat.

This was well illustrated by the first battle fought between the Korean People's Army and the U.S. forces in the war.

According to the operational plan of President Kim Il Sung, the KPA promptly stopped the enemy's attack and switched over to a counteroffensive, advancing southward after liberating Seoul City.

At that time, a KPA unit, which was advancing towards Phyongthaek and Taejon, encountered an advance unit of the U.S. ground forces in Osan area. The U.S. unit was made up of the 1st Battalion of the 21st Regiment and the 52nd Artillery Battalion under the 24th Division, called "Smith commandos".

In this first battle with the U.S. forces, the 30th Tank Regiment of the KPA overpowered the enemy's artillery battalion, while the KPA 18th Infantry Regiment encircled the commando unit to annihilate it, winning in the battle.