In June, 1950, the US military presence in Korea was a 500-man Korean Military Advisory Group (KMAG). Its departing commander, General William L. Roberts, USA, gave an interview to a Time reporter in which he described the ROK army as "The best damn army outside the United States."
The General's opinion regardless, at least one army outside the US, only days later, proved itself devestatingly superior to the ROKs, who were sparsely equipped with used American small-arms, some short-range M3 105 howitzers, a few 2.36" bazookas, no armor, no mortars heavier than 81mm, no medium artillery and no combat aircraft.
The NKPA, the In Min Gun, were well-armed, well-trained, with a core of combat veterans, tightly organized into thirteen infantry and one mechanized divisions, and closely supported by a hundred Yak and Stormovik tactical aircraft, with 150 T-34 tanks, 120mm mortars, 122mm howitzers, 76mm SPGs, and 45mm ATGs. Basically, the In Min Gun were armed with the whole family of outstanding soviet infantry weapons.
As always, the soldiers paid the price for the politicians' arrogance and errors. Truman felt sorry, and fired his Secretry of Defense Johnson, but millions of ordinary people died or had their lives destroyed because of the mistakes of the Truman Administration and our Joint Chiefs of Staff.
Such is life.
These lightly armed troops shown above, after the main ROK forces were trapped and destroyed by the North Korean surprise attack north of the Han, did the best they could.
God bless them.