and 27th Armies of the IX Army Group were reported to be off the front in the area north of Chuncheon and the group's 26th Army possibly in the same vicinity. The XIII Army Group apparently was still on the east central front, its 40th Army astride Route 17 just above Chuncheon and the 39th Army next to the east with its bulk between the Hwacheon Reservoir and the Soyang River and light forces occupying a bridgehead below the Soyang between Chuncheon and the river town of Naep’yong-ni some upstream to the northeast. On the basis of these dispositions, General Van Fleet continued to believe that the main enemy effort would come in the west central sector, probably toward the Han River corridor, and would be made by five armies, the 60th, 15th, 12th, 27th and 20th. He also anticipated strong attacks toward Seoul over Route 1 and through the Uijeongbu corridor as well as another on the Chuncheon-Hongcheon axis. Second offensive (15–22 May) Even though the PVA forces lost the strategic initiative after the first offensive per Peng's reports, Mao still insisted that the second phase of the offensive be carried out. On 15 May 1951, the PVA Command recommenced the Second Spring Offensive and attacked the ROK and US X Corps in the east at the Soyang River with 150,000 men. After taking the Hwacheon Reservoir and gaining initial success, they were halted by 20 May. Aftermath The spring offensive would be the last all-out offensive operation of the PVA for the duration of the war. Their objective to permanently drive the UN out of Korea had failed. The UN soon launched its May–June 1951 counteroffensive which erased all gains of the spring offensive and returned the UN forces to Line Kansas approximately north of the 38th Parallel, while some UN units advanced further north. A series of smaller skirmishes followed as the UN established the Jamestown Line as the main line of resistance. The presence of UN forces at the northeast of the 38th Parallel, prompted the PVA Command to plan a limited offensive dubbed the "Sixth Phase Campaign". But the armistice negotiations that began on 10 July 1951 at Kaesong forced both sides to dig in at their respective positions across the 38th Parallel. The mobile warfare of rapid movement that dominated the early stages of the war has completely eclipsed following the offensive and the