The Americans took longer than they are accustomed to solve the North Korean defense.
To avoid these South Korean defenses, North Korea's infantry would use tunnels dug by its army underneath the border.
Faced with the South Korean defense, the Chinese had prepared for well over a month for the offensive.
The Chinese artillery units began to bomb the South Korean defenses at 16:30 on December 31.
I don't mean to suggest that the United States must and should be involved in every facet of Korean defense.
Intelligence analysts say that one reason may be to test South Korean defenses.
At first tenacious North Korean defense halted the Marines' push.
Destroyer fire and bombing runs silenced the North Korean defenses.
The Japanese overwhelmed the Korean defenses by scaling the walls under cover of the arquebuses.
Then armored forces would try to burst through the American and South Korean defenses.