Chinese prisoners taken during the first three weeks of April 1951 told all they knew with no apparent reluctance, just as Japanese captives had given information in World War II. Inconsistent as it may seem that fanatical Asian soldiers should prove so cooperative, such was the penalty the enemy paid for insisting on resistance to the last ditch. Since the possibility of surrender was not considered, CCF prisoners were taught no code of behavior and answered questions freely and frankly. POW interrogations were supplemented by captured documents revealing that the Chinese prided themselves on a new tactical doctrine known as “the roving defensive,” put into effect in the spring of 1951. It meant “not to hold your position to the death, but to defend against the enemy through movement,” explained a secret CCF directive dated 17 March 1951. “Therefore, the wisdom of the roving defensive is based on exhausting the enemy without regard for the loss or gain of some fighting area or the immediate fulfillment of our aims.”[150] [150] This section is based upon the following documents: IX Corps _CmdRpt_ 5, Apr 51, Sec 3, Intelligence; 1stMarDiv _HD_, Apr 51; _PIR_ 171, 179, 180. It was admitted that the CCF soldier must work harder, “because the troops will have to construct entrenchments and field works in every place they move.” But the advantages were that “roving warfare can conserve our power, deplete the enemy’s strength, and secure for us more favorable conditions for future victory. Meanwhile, the enemy will make the mistake once again, and collapse on the Korean battlefield.” The last sentence evidently refers to the UN advance of late November 1950 that was rolled back by a surprise CCF counteroffensive. Chinese strategists seem to have concluded that their “roving defensive” had made possible another such offensive victory in the spring of 1951. At any rate, prisoners questioned by the 1st Marine Division and other IX Corps units agreed that the CCF 5th Phase Offensive was scheduled to begin on 22 April 1951. The IX Corps zone was said to be the target area for an attempted breakthrough.[151] [151] EUSAK, IX Corps and 1stMarDiv G-2 _PIR_s, 1–20 Apr 51. Marine G-2 officers recalled that prisoners gave information on the eve of the CCF offensive in November 1950 that proved to be astonishingly accurate in the light of later events. For it was a paradox that the Chinese Reds, so secretive in other respects, let the man in the ranks know about high-level strategic plans. In the spring of 1951 it mattered little, since air reconnaissance had kept the Eighth Army well informed as to the enemy buildup. Prisoners were taken in the IX Corps zone from the following major CCF units during the first three weeks of April: 20th Army (58th, 59th, and 60th Divisions), estimated strength, 24,261; 26th Army (76th, 77th, and 78th Divisions), estimated total strength, 22,222;