1969
By the end of Commando Hunt I, the first dry season offensive of the campaign (15 November 1968 to 20 April 1969), the Air Force estimated that 7,322 enemy trucks had been destroyed. At the rate of attrition claimed in December, however, the PAVN transportation network should have been destroyed in only a month and a half. It also claimed that 20,723 enemy had been killed by air, 15 percent of the total number believed to have been travelling on, operating, or defending the trail." 56 allied aircraft were shot down during the operation by an estimated 600 communist anti-aircraft weapons. The end of Rolling Thunder, it seemed, had freed up not only U.S. aircraft, but also allowed more PAVN anti-aircraft units to move south to defend the trail. During the year the North Vietnamese began deploying longer-ranged and radar-directed 85 and 100 mm guns.
For the U.S. program there were, of course, teething troubles. There was a lack of sufficient numbers of sensor strings and controlling the number of aircraft available for the missions proved problematic. These difficulties could be remedied. Commando Hunt II (1 May through 31 October 1969), however, was thrown off track by phenomena that the Air Force could do absolutely nothing about. The first wet season offensive was hampered by atrocious weather, especially heavy rain (48 inches of rain in July alone). The real problem for U.S. planners was a lack of sufficient intelligence on the numbers of infiltrators, the amount of supplies being transported, the number of trucks operating, the specific locations of targets in a rapidly changing environment, and the infrastructure of the system. This lack of real intelligence forced the Air Force to basically take its best guess as to PAVN numbers, intentions, and limitations. For instance, Air Force intelligence claimed that 9,012 enemy trucks were destroyed during 1969. Yet, an even lesser estimate of trucks destroyed by the Defense Intelligence Agency only resulted in their computer model reaching zero (where the enemy was supposed to be out of trucks) no fewer that 14 times during the same time period.
The Air Force's computing of communist personnel losses, according to Air Force historian Bernard Nalty was "based on so many assumptions that the end product represented an exercise in metaphysics rather than mathematics." He was seconded by historian Earl Tilford who explained that
"Americans expected progress, or at least quantifiable measures of success...It is in their nature to do so. Commando Hunt provided the figures that sated that appetite. Productivity epitomized what the war had become: an exercise in management effectiveness."
It was, however, difficult for the Air Force to do otherwise. Observation of the trail from the air was difficult at best. Human intelligence was provided by CIA-backed Laotian irregulars and Thai volunteers operating from the western side of the system while the eastern side was covered by SOG. The depth of penetration by these reconnaissance efforts was hampered by the same man who had the last word in the bombing effort, Ambassador William H. Sullivan in Vientiane. The ambassador (with the full backing of the State Department and the CIA) maintained a firm hold over all military operations conducted within the supposedly "neutral" Kingdom of Laos. All targets had to be pre-approved either by Sullivan himself or by the air attaché within Project 404, the understaffed U.S. military operations center within the embassy.
By the end of the year the Americans felt that they were better prepared to deliver destruction to the trail system. During Commando Hunt III (1 November 1969 to 30 April 1970), the Air Force claimed that 6,428 enemy trucks destroyed and another 3,604 damaged. 60 aircraft were shot down during this phase of the campaign by an estimated 743 anti-aircraft weapons. This increased number of aircraft losses forced the Air Force to decree that flak suppression missions would accompany the bombers on missions over the trail. Armed with cluster bomb units (CBUs), the fighter bombers were poised to pounce upon any enemy anti-aircraft positions identified by other aircraft.
On the other side of the fence, the North Vietnamese transported and/or stored 70,000 tons of supplies in 3,000 trucks with a net loss of 13.5 percent during the year. During the same period about 80,000 PAVN troops made the trip south. A new North Vietnamese logistical effort, discovered by U.S. intelligence in late 1968, was a petroleum, oil, and lubricants (POL) pipeline running southwest from the North Vietnamese city of Vinh. By early the following year the pipeline had crossed the Laotian frontier and by summer it had reached Muong Nong and the approaches to the Ashau Valley. The plastic line, assisted by numerous small pumping stations, could transfer diesel fuel, gasoline, and kerosene all in the same pipe.
Read more about this topic: Operation Commando Hunt