From the outbreak of the Korean War and the invasion of South Korea by the North, the KPA had enjoyed superiority in both manpower and equipment over both the ROK and the UN forces dispatched to South Korea to prevent it from collapsing.
The KPA tactics were to aggressively pursue UN forces on all avenues of approach south and to engage them aggressively, attacking from the front and initiating a double envelopment of both flanks of the unit, which allowed the KPA to surround and cut off the opposing force, which would then be forced to retreat in disarray, often leaving behind much of its equipment.
From their initial June 25 offensive to fights in July and early August, the KPA used these tactics to effectively defeat any UN force and push it south.
However, when the UN forces, under the Eighth United States Army, established the Pusan Perimeter in August, the UN troops held a continuous line along the peninsula which KPA troops could not flank, and their advantages in numbers decreased daily as the superior UN logistical system brought in more troops and supplies to the UN forces.

When the KPA approached the Pusan Perimeter on August 5, they attempted the same frontal assault technique on the four main avenues of approach into the perimeter.
Throughout August, the KPA 6th Division, and later the 7th Division engaged the US 25th Infantry Division at the Battle of Masan, initially repelling a UN counteroffensive before countering with battles at Komam-ni and Battle Mountain.
These attacks stalled as UN forces, well equipped and with plenty of reserves, repeatedly repelled KPA attacks.
North of Masan, the KPA 4th Division and the US 24th Infantry Division sparred in the Naktong Bulge area.
In the First Battle of Naktong Bulge, the KPA division was unable to hold its bridgehead across the river as large numbers of US reserve forces were brought in to repel it, and on August 19, the KPA 4th Division was forced back across the river with 50 percent casualties.
In the Taegu region, five KPA divisions were repulsed by three UN divisions in several attempts to attack the city during the Battle of Taegu.
Particularly heavy fighting took place at the Battle of the Bowling Alley where the KPA 13th Division was almost completely destroyed in the attack.
On the east coast, three more KPA divisions were repulsed by the ROK at P'ohang-dong during the Battle of P'ohang-dong.
All along the front, the KPA troops were reeling from these defeats, the first time in the war their tactics were not working.
From the outbreak of the Korean War and the invasion of South Korea by the North, the KPA had enjoyed superiority in both manpower and equipment over both the ROK and the UN forces dispatched to South Korea to prevent it from collapsing. The KPA tactics were to aggressively pursue UN forces on all avenues of approach south and to engage them aggressively, attacking from the front and initiating a double envelopment of both flanks of the unit, which allowed the KPA to surround and cut off the opposing force, which would then be forced to retreat in disarray, often leaving behind much of its equipment. From their initial June 25 offensive to fights in July and early August, the KPA used these tactics to effectively defeat any UN force and push it south. However, when the UN forces, under the Eighth United States Army, established the Pusan Perimeter in August, the UN troops held a continuous line along the peninsula which KPA troops could not flank, and their advantages in numbers decreased daily as the superior UN logistical system brought in more troops and supplies to the UN forces.
When the KPA approached the Pusan Perimeter on August 5, they attempted the same frontal assault technique on the four main avenues of approach into the perimeter. Throughout August, the KPA 6th Division, and later the 7th Division engaged the US 25th Infantry Division at the Battle of Masan, initially repelling a UN counteroffensive before countering with battles at Komam-ni and Battle Mountain. These attacks stalled as UN forces, well equipped and with plenty of reserves, repeatedly repelled KPA attacks. North of Masan, the KPA 4th Division and the US 24th Infantry Division sparred in the Naktong Bulge area. In the First Battle of Naktong Bulge, the KPA division was unable to hold its bridgehead across the river as large numbers of US reserve forces were brought in to repel it, and on August 19, the KPA 4th Division was forced back across the river with 50 percent casualties. In the Taegu region, five KPA divisions were repulsed by three UN divisions in several attempts to attack the city during the Battle of Taegu. Particularly heavy fighting took place at the Battle of the Bowling Alley where the KPA 13th Division was almost completely destroyed in the attack. On the east coast, three more KPA divisions were repulsed by the ROK at P'ohang-dong during the Battle of P'ohang-dong. All along the front, the KPA troops were reeling from these defeats, the first time in the war their tactics were not working.
Second Battle of Naktong Bulge