The Pohang area had great strategic importance because it included a significant stretch of the Eighth Army main supply route (National Route 29), housed several key road junctions, included the only protected port on the east coast still in UN hands, and was the site of K-3 one of the few modern airfields in eastern Korea.

This mission was confirmed on 8 January, but it had by then been modified to include the entire 1st Marine Division which was not assigned to a corps, but would instead be directly under Eighth Army operational control.

The division staff cut orders on 9 January, and the Marines began moving out the next day with the maneuver elements going by truck and the support units by air, rail, and ship.

Upon arrival at Uisong the next day, the regimental combat team began patrolling a 30 miles (48 km) section of road.

A key crossroads about 40 miles (64 km) inland from the sea, it was the site of US X Corps' rear headquarters as well as two dirt airstrips (one of which was long enough to handle cargo planes, but the other able only to service light observation aircraft and helicopters).

Instead, he ordered the Marines to defend an east-west line just north of the Andong-Yongdok Road and to simultaneously protect the north-south-running Eighth Army main supply route.

Should he deploy to guard against an all-out attack on the main line of resistance by PVA/KPA regular forces from the north or be prepared for counter-guerrilla operations against small groups of infiltrators?

Small KPA bands had already proved extremely troublesome by intermittently cutting supply lines and occasionally attacking outposts between Wonju and Taegu so continued guerrilla actions were considered probable.

Smith, therefore, decided to emphasize mobile security operations and made linear defense a secondary mission.

[1]: 353 The enemy threatening Pohang was believed to consist of about 6,000 light infantry troops from Major general Lee Ban Nam's 10th Division.

[1]: 353 The 1st Marine Division zone of action was roughly 40 miles (64 km) square, an area composed of 1,600 square miles of extremely rugged interior terrain enclosed by a semicircular road network joining the coastal villages of Pohang and Yongdok with the inland towns of Andong and Yongchon.

A secondary road (Route 48) joined Andong in the northwest corner with centrally located Chinbo and Yongdok on the coast.

The valley lowlands were dotted with small villages whose adjoining terraced rice paddies edged roadways and agricultural flat lands.

The center of the Marine area of responsibility consisted of snow-capped mountains traversed only by a series of winding trails and narrow pathways that worked their way up and down the steep ridges.

These veteran campaigners knew that counter-guerrilla operations were primarily small unit actions that tested individual stamina and required strong leadership at the fire team, squad, and platoon levels.

Squad and platoon-sized ambushes set up nightly along mountain trails or fanned out to cover likely avenues of approach to nearby villages.

Motorized road patrols consisted of machine gun-mounted jeeps that roved the main supply route at irregular intervals.

Four days later a patrol from the 1st Marines discovered an estimated KPA battalion near Mukkye-dong south of Andong just before sunset and promptly got the best of a one-sided exchange of small arms and mortars.

Nightfall prevented full pursuit and the KPA escaped under cover of darkness by breaking into squad and platoon-sized exfiltration groups.

On the 26th, 1st Battalion, 7th Marines isolated a KPA company atop Hill 466 that held the attackers at bay with mortars, small arms and hand grenades.

As a consequence of these losses Lee ordered his troops to cease offensive operations until they could withdraw into the mountains to regroup.

This pattern continued throughout January and February 1951, much as it had in the Moro Rebellion in the Philippines at the turn of the century and would again in the Vietnam War little more than a decade later.

Other indicators of KPA desperation were that women were increasingly being drafted to serve as porters and combat troops were donning captured American clothing to cover their escape.

Although the 10th Division still could muster about 1,000 men, captured dispatches indicated PVA headquarters ordered the remaining KPA to break out of the Marine encirclement.

There were also a large number of non-battle casualties, primarily the result of frostbite or minor injuries, most returned to their units.

[1]: 362–3 The assessment of the status of the KPA 10th Division would prove to be incorrect; the division had maintained a formal organization of a headquarters and three regiments and with a surviving strength of about two thousand and had managed by the opening of Operation Ripper on 7 March 1951 to slip north through the Taebaek Mountains to the Irwol Mountain region, 30 miles (48 km) northeast of Andong.