This shows why the Marines, although providing
air support when possible through Captain Stamford, were unable
to rescue 7th Infantry Division's 31st RCT, which was destroyed
only a few miles away, on the east coast of the Chosin
Reservoir.
The Hagaru-ri valley was surrounded by
commanding hills. Those vague shadows in the upper
middle are still more and higher snow covered
mountains. To put in a perimeter defense even on the
near heights would mean manning about a four mile line,
on the reverse slopes. This would take at least two
infantry regiments. Lt. Col Tom Ridge, 3 Battn 1st
Marines, had at his disposal for defense of Hagaru only
two reinforced companies and a 6-gun 105mm battery.
With the few available tanks it was just possible to man a
partial inner perimeter defense, on flat ground around
Hagaru, and pray the enemy didn't have artillery to
enfilade the camp. To weaken that defense force further
by deploying units out of the perimeter in an attempt
to relieve an Army force several times its size, while
itself under attack by about the same size force
attacking the Army RCT, would have been to risk the
withdrawal route for the 5th and 7th Marines, and the
whole of the First Marine Division.
In the event, there was much savage
fighting just for East Hill, the immediate heights,
before and after the 5th & 7th Marines reached
Hagaru.