Robertson, the Army staff officers "couldn't quite visualize how the rockets would every now and then fall in Da Nang airfield [with] the Marines patrolling . . . the way they had used to ... ."9
The Army brigade, therefore, founded its tactical plan on "a mobile concept with no fixed fire support bases." Essentially this meant garrisoning permanently only the cluster of rear installations behind Division Ridge and Hill 65, which would serve as an artillery position, and leaving most patrolling of the Rocket Belt to the South Vietnamese. The Army infantry and armored cavalry, instead of relieving the Marines in place, were to deploy deep in the mountains and the Arizona Territory, outside the usual III MAF AOs. There, the Army troops would conduct continuous search and destroy operations aimed at intercepting enemy forces well away from Da Nang. Marines familiar with the defense problems in Quang Nam had private doubts about the validity of this strategy, but they could not dictate another Service's methods of operation.10
Operations in Quang Nam, January-February 1971
The pattern of war in Quang Nam showed little change during the first months of 1971. Ill MAF now estimated total North Vietnamese and Viet Cong strength in the province at about 13, 900 men; the 1st Marine Division estimate was lower, about 9, 000 ef�fectives. Whatever the Communists' actual numbers, all allied intelligence agencies agreed that combat loss�es, combined with a reduced flow of replacements from North Vietnam and local recruiting difficulties, were reducing enemy forces in both quantity and qual�ity Casualties among military leaders and VCI had dis�rupted enemy command and control. The autumn floods and storms had destroyed many cached supplies and resulted in the deaths of perhaps 1, 000 NVA and VC from hunger and exposure. Prisoners and Hoi Chanhs continued to report deteriorating morale, and even occasional mass refusals to fight, among both main forces and guerrillas.11
Nevertheless, as Colonel Edward A. Timmes, the 1st Marine Division Assistant G-2, pointed out, the enemy still constituted:
... a force in being,, . that not only can give us con�tacts but more important. . . can make influence upon our population, for example, if [the enemy] throws three rock�ets once a month, and they do not even hit the airfield, it still achieves his purpose. He has let everybody know, within sight and sound, or even where they see the Marines running around because of this, . . that he can still make these attacks. Whether successful or not, he still achieves a large portion of his goat . . .,12
Communist tactics during early 1971 conformed to Colonel Timmes' expectations. Avoiding Marine units, the enemy concentrated on harassment of ARVN, RF, and PF positions by occasional attacks by fire and small ground assaults and maintained steady terrorist pres�sure on GVN officials and civilians through terrorism.
As in previous years, enemy offensive activity usually occurred during three-to-six-day "high points" coin�ciding with periods of moonless nights. Most of these upsurges of aggressiveness during the first weeks of 1971 were part of the enemy's K-800 Spring Offen�sive. Throughout January, the allies detected increas�ing infiltration of small NVA and VC main force detachments into the lowlands from mountain base areas. Increased infiltration was normally a harbinger of intensified Communist activity generally character�ized by attacks by fire with limited ground follow-up. From the night of 31 January to 1 February, the ex�pected offensive began with a series of nearly simul�taneous mortar and ground attacks on CUPP and militia units. The enemy also fired eight 122mm rock�ets at Da Nang airfield. Three of the rockets failed to explode; the others set fire to a 50, 000-gallon fuel dump, slightly damaged two Marine KC-130s, killed a Vietnamese woman, and wounded two U.S. Navy men. The KC-130s, which were parked near the blaz�ing fuel tanks, would have been destroyed except for the courage of five enlisted Marines from Sub-Unit 1 of Marine Aerial Refueler Transport Squadron 152 and MABS-11. These Marines braved intense heat and danger of explosions to tow the big planes to safety.13
The K-800 Campaign continued through February with flurries of small-scale attacks. On 21 February, the enemy hit Da Nang with eight more 122mm rock�ets which destroyed a C-130 transport. The same night, seven more rockets landed on Hill 55, wounding one Marine. Four more rockets struck the hill three days later, but exploded harmlessly outside the perimeter. After a month of activity, the results of the K-800 Campaign in allied casualties and material losses were minor compared to the scale and cost of the NVA and VC effort. Nevertheless, the III MAF intelligence sec�tion reported that the offensive "was successful in that the enemy was able to demonstrate his continued presence to the civilian population despite allied de�terrent operations."14
Deterrent operations were continuous and exten�sive. Throughout January and February, the South
