Well I believe the Chinese intervention in Korea could be divided into two phases. The first phase consisted of when the PVA had complete surprise on the tactical, operational, and strategic levels. They had the UN forces completely offguard and complete initiative and control of the situation. Operations during this time were characteristic of Chinese guerilla tactics, involving infiltration attacks, night combat, envelopment, and psychological warfare tactics. PVA units would probe and infilitrate UN positions to determine platoon to company sized pockets which they could isolate and completely destroy during night attacks. These attacks were carried out at various points in the UN line, giving the impression that the Chinese were everywhere at once, while in reality the Chinese were specifically targeting certain, critical areas in the UN line and achieving local numerical superiority at the points. However, as the war dragged on and moved further south, the Chinese begin to lose that initiative. The UN forces also became much better prepared, dug in, and begin to change the way in which they positioned their forces. Also, the terrain in the south was less mountainous and more open than in the North, and allied air operations, especially recon operations became much more successful. After the UN retook Seoul, they enjoyed near total initiative in the drive back north. The Chinese and North Koreans were forced into a defensive, positional war where they were at a massive firepower deficit. Any large concentrations of PVA/KPA troops were subjected to intense air bombardment, so the only way the PVA/KPA could respond to allied breakthroughs was through mass concentration of troops at the point of the breakthrough. The only options available to the PVA to counterattack and retake lost ground was also through massing of troops at the point of engagement. However, once the war moved back into more mountainous terrain, and where the PVA were able to dig in and fortify as well as receive more artillery, they were able to hold back the UN forces in the same manner the UN had enjoyed earlier in the conflict- defense from prepared positions, control of the high ground, and ability to focus massive firepower at the point of breakthrough. Faced with those set of conditions, the UN forces attempted no major offensives for the last year of the war. In conclusion, yes human wave attacks did occur on the side of the PVA during the Korean War, but only during the most desperate part of the war during which the Chinese, overextended at a serious firepower deficit had no other means to hold back the UN counteroffensive.
