It very nearly ended in a North Korean victory. Had the United Nations commitment come later or the political decision been made to not commit US forces at all the North Koreans would have swept into Pusan very quickly and the war would have been over. Glorious Great Leader Kim Il-sung would have united homeland against Imperial Puppets.
United under South Korea equally only requires no intervention on the part of the People’s Republic of China. The United Nations Forces were nearly at the Yalu River when the PRC Volunteer Army intervened.
the USA takes Chinese warnings literally and only sends ROK units up to the Yalu. Cook, UN troops were attacked by the Chinese the first time well before they all got to the Yalu and they dismissed it altogether. Douglas MacArthur had learned absolutely nothing from his Philippines disaster and was even more inexcusably stupid this time.
The Chinese are still going to intervene. The Chinese were planning to send troops in even before the Americans reached the 38th parallel IIRC and simply sending ROK troops north is not going to curtail a Chinese intervention.
If the French are more successful in the French Indochina War and start winning, maybe the Chinese will intervene down there instead, which could lessen/prevent their involvement in Korea. Just a thought.
Cook, UN troops were attacked by the Chinese the first time well before they all got to the Yalu and they dismissed it altogether.