This single page analysis of the North Korean People's Army and the Army of South Korea will clue you in pretty quickly as to why President Truman hastened to get the necessary beans, bullets and band-aids delivered to the South as quickly as he did. This comparison, written by the U.S. Army History Section, clearly indicates that the North Korean force was intended to be an offensive army; well-equipped and fast-a-foot; the army of the South, by comparison, was intended (for some unexplained reason) to fight limited engagements - rather than prolonged, corps sized campaigns.
It was no surprise to the assorted military insiders of the world when the South Korean capital of Seoul was seized three days into the war.
Click here to read how a defeated and occupied Japan was able to find a new identity and resolve as a result of the Korean War.