The United States Army, at the same time, had a total active-duty strength of about 591,000 men in ten combat divisions. Around 360,000 of those troops were home (WWII had ended only five years before) with the remaining 231,000 serving in various overseas commands. (A total of about 108,500 were serving in the Far East.)

According to the US Army history of the Korean Conflict:

By late 1949 talk of a North Korean invasion was almost routine in intelligence circles, but it went unnoticed against the background of threatening Communist activities in other parts of the world- Southeast Asia, western Europe, and the Middle East. In the early summer of 1950 senior American observers discounted the likelihood of a North Korean invasion. Both Maj. Gen. Charles A. Willoughby, the FEC G-2 (intelligence officer), and the American embassy in Seoul opined that an attack was unlikely and that the North Koreans would continue to employ guerrillas and psychological warfare. The officers of the KMAG felt that an attack by North Korea was not imminent and, if it happened, they thought that the South Koreans could repel it. Since the United States had no plan to counter an invasion, any debate about an American intelligence failure regarding the North Korean attack was academic.

In June of 1950, talk of an invasion became reality.