The decision to intervene was one matter, but the question was: with what troops? The only readily available US troops in a shrunken armed forces were in Japan. The forces in Japan, however, were not ready for combat, but there was no one else available. The first unit to be called on was the 1st Battalion, 21st Infantry Regiment, 24th Infantry Division, commanded by Colonel Charles Bradford Smith. On the evening of June 30, he was ordered to proceed to Korea. Four days later, Smith's understrength battalion, joined by six 105-mm howitzers now named Task Force Smith, were heading to the front. Their job was to slow down the North Korean advance. Smith picked a point just north of the village of Suwon, where a series of low hills crossed the road. At 3:00 AM, July 5, the men arrived at the spot and began to dig in. Five hundred and forty of Smith's men straddled the highway, ready to attack North Korean troops as they headed south. At 8:06 AM, the first North Korean tanks were within range of Smith's artillery, and he opened fire. The artillery fire failed to stop the tanks, and they rolled on. As they got closer, they came under bazooka fire, which stopped two of the tanks; but the others moved through, hardly paying any attention to the American forces. Since the Americans had only 9 rounds of armor-piercing shells, there was nothing that could be done to stop the tanks. Forty tanks in all passed the American positions.

At 11:00, the first of 4,000 Korean infantrymen, spearheaded by four tanks, appeared. When the North Koreans were 1,000 yards away, Smith opened up with everything he had. The North Koreans regrouped and, before long, they were attempting to cut off Smith's force. After two hours of fighting, it was clear that Smith force could not hold off for much longer a force eight times larger. Smith realized that, if he did not order a withdrawal, all his men would be annihilated, so he ordered a withdrawal. Most of his men eventually made their way back to American lines.