One problem with surrounding a powerful
fighting force is containing them at the point of their
counter-attack. The besieging force needs to carry out
an attack themselves, to force some sort of withdrawal,
and then mass sufficient strength at the point of
counter-attack to stop it. Even if the probable defense
direction of withdrawal is an exposed road, such as the
MSR (Main Supply Route) at the Reservoir, sufficient
surrounding force needs to be maintained to prevent the
besieged from forcing a different bypass. And even in
the road is taken, a determined fighting defense will
be very hard to contain at any single point, even with
well-placed roadblocks supported by enfillading fire
from surrounding heights. Although surrounded by far
larger numbers of troops, resolute and veteran troops,
the Marines simply took their losses, took those high
grounds, crushed the roadblocks, and kept going. For
thirty-five bloody miles.