Secret documents dug out of the Cu Chi tunnels in 1966 exposed the Viet Cong’s entire Saigon area clandestine organization to total destruction.
In Asian mythology there is a dragon that lives underground guarding the king’s treasure, most precious of which is the pearl of wisdom and power, kept safe under the dragon’s jaws. On January 11, 1966, an Australian soldier crawled out of a narrow, dark Viet Cong tunnel north of Cu Chi dragging a leather satchel fastened together by two straps and buckles. He did not know it, but inside that satchel was the key to victory in South Vietnam, equivalent to the pearl of wisdom and power in the myth. That victory could have been won in 1966, but it was not. The squandering of one of the war’s biggest intelligence bonanzas— which could have made the 1968 Tet Offensive impossible—has been little noted by historians but certainly ranks among the Vietnam War’s biggest lost opportunities.
During the entire Vietnam War, only one operation conducted by the Free World Military Forces (a designation for all the various non-Communist military units operating inside and in support of South Vietnam) had the potential to bring victory to the government in Saigon. Code-named “Crimp,” it was conducted in January 1966 by the U.S. 173rd Airborne Brigade (Separate). The operation marked the beginning of the “tunnel rat” legend.
As Commander of the Military Advisory Command, Vietnam (MACV), General William C. Westmoreland’s priority in 1965 was to use his surging numbers of brigades and divisions to upset the Viet Cong/North Vietnamese Army timetable and buy time for his allocated formations to settle into their assigned locations and begin largescale operations in 1966. Besides seeking out enemy main force regiments to engage them in battle, Westmoreland’s units swept the areas in which the arriving forces would establish base camps. The first U.S. Army ground force formation deployed to the III Corps Tactical Zone in South Vietnam in May 1965 was the 173rd Airborne Brigade from Okinawa. The brigade was commanded by Brig. Gen. Ellis W. Williamson and consisted of two parachute infantry battalions, the 1st and 2nd Battalions, 503rd Infantry (1-503 and 2-503), plus airborne artillery, cavalry and a support battalion. Assigned to the 173rd was an Australian battalion group made up of the 1st Battalion of the Royal Australian Regiment (1/RAR), with Australian and New Zealand 105mm artillery batteries, and a troop of M-113 armored personnel carriers from the Prince of Wales Light Horse. The 173rd was a powerful mobile force, and into December 1965 it fought some notable actions throughout III CTZ.
In late 1965, MACV intelligence placed the Viet Cong headquarters for the Saigon district—their Military Region 4—near the Ho Bo Woods, north of Cu Chi town. The 173rd Airborne Brigade and the 3rd Brigade of the U.S. 1st Infantry Division (the Big Red One) were tasked to sweep the area, with the 173rd to attack the VC headquarters and the Big Red One’s brigade to screen the adjacent sector to the south. On New Years Day, 1966, the 173rd deployed on Operation Marauder from its base at Bien Hoa to the Plain of Reeds, west of Saigon, while simultaneously preparing for Operation Crimp.
Crimp was planned as an airmobile as sault by the 173rd on the enemy headquarters location, to be followed by several days for exploitation, then a return to Bien Hoa to prepare for further operations. As a 1963 graduate of the Australian Defense Language School, I was the only linguist available in the 1st Battalion of the Royal Australian Regiment at the time. The 173rd brigade headquarters also had a special team of linguists from MACV, led by Sergeant Sedgwick “Wick” Tourison, that waited for the detainees, prisoners and captured documents from the Viet Cong headquarters that would be sent back by the units in the field.
On January 8, the 173rd made three battalion-sized air assaults into landing zones around the Viet Cong headquarters southwest of the Ho Bo Woods. The plan was for the Australians to land first to the east of the headquarters and secure a blocking position in a populated area along a main road. Then the 1-503rd would land to the north and the 2-503rd to the southwest. The two U.S. battalions would make crisscross sweeps through the area of operations and push the enemy onto the Australians. The brigade from the Big Red One took the area to the south.
As it turned out, Viet Cong headquarters actually was in the blocking position assigned to the Australians, which arrived in a hot landing zone and soon found action against the Viet Cong security battalions— the Quyet Thang and Cu Chi 7th. As they fought their way through, almost every platoon found tunnels. As soon as the enemy was driven away, exploration of the underground hideouts began. Only small skinny men, armed just with a flashlight and pistol, could fit into the tunnels. As the infantry and combat engineers crawled and wriggled they soon found they were in a huge underground network, far bigger than anything found since the 173rd had begun operating in the area in May 1965. The tunnel system went down three, four or more levels to the water table, and linked the local villages and hamlets. While some of the tunnels were newly dug, others were so old that moss grew on the walls.
High-powered “Mighty Mite” air pumps were brought in to force tear gas and smoke into the tunnels, to drive out the Viet Cong and expose the tunnel entrances. The tactic didn’t work, as the entrance covers were too heavy to be dislodged by air pressure. With a map and pencil in hand, I hovered above in a Huey to mark the locations of colored smoke expected to be seen jetting out of air holes and trapdoors, but the 37 smoke grenades dumped into the tunnels produced no indicators visible from the air or on the ground. Furthermore, the residual gas and smoke remained a hindrance to the Australian tunnel searchers.
The commander of the Aussie combat engineers, Captain Alex MacGregor, realized that a map of the found tunnels had to be made to further guide the exploration effort and to detect emerging patterns. He had his men take a compass and lengths of field telephone cable into the tunnels to shoot azimuths and measure the distances to the turns and trapdoors. All of this stressful underground exploration was done in near-darkness and without knowledge of what the enemy might do at any moment. The Aussies had no breathing apparatus in the badly ventilated tunnels, and many had to be rescued when they lost consciousness for lack of air. One combat engineer, Corporal Bob Bowtell, was too big for the tunnels but chose anyway to lead by example. He became wedged in a tunnel and suffocated in the bad air. Nevertheless, more men still went down into the darkness and the unknown.
So much material was flowing from the tunnels in the Australian sector that I could only look briefly at any given bundle of documents, or check the first couple of files in a box, tie on a tag with details of date, location and capturing unit, and have the bags and boxes stacked at the landing zone for evacuation to brigade headquarters. Anything determined to be unimportant was thrown onto a fire built nearby. As soon as the first bags of captured documents were opened at brigade headquarters, Wick Tourison’s team realized that everything else previously captured by MACV was now obsolete. Day after day, more important documents were dragged out of the tunnels. The secret world of the Viet Cong had been cracked wide open.
As it became clear that the enemy headquarters was in the Australian location, General Williamson brought his U.S. battalions up alongside 1/RAR. To the north the 1-503rd fought several actions against dug-in VC, keeping them off balance and finding more tunnels, one with six levels. To the south, the 2-503rd searched its area but found little to report. Farther south, the 3rd Brigade from the 1st ID engaged snipers firing from the tunnels. Outside the 173rd area of operations, aggressive cross-country sweeps by Americans and Australians prevented the enemy from mounting a counterattack against the U.S. paratroopers. Meanwhile, the Australians continued to search the tunnel system, but also maintained a strong screen of patrols and ambushes above ground that kept the Viet Cong from reentering the area. Frequent small unit actions were fought by day and night and a number of Viet Cong who refused to surrender were killed in the tunnels.
When one of the tunnel searchers brought me the two-strap leather satchel and I began perusing its contents, I immediately recognized that this was probably was the most important item found in the entire tunnel complex—the master file of detailed information on all the Viet Cong in the region. Meticulously recorded across large sheets of paper were the complete backgrounds of key members of the Viet Cong organization in the Saigon vicinity. Arranged in columns were the individuals’ real names, code names, places and dates of birth, occupations, Communist Party membership details and party assignments. I took the satchel to Australian commander Lt. Col. Alex Preece and explained to him what it contained and suggested it be sent directly to MACV. I then returned to continue the work of assessing the mass of material still being retrieved from the underground labyrinth.
Because of the critical intelligence finds, Operation Crimp was extended, finally concluding on January 14, 1966. The 173rd had captured an important Viet Cong headquarters, removed eight truckloads of vital documents and tons of weapons and supplies— but not without a serious fight. The brigade’s casualties were 23 killed and 102 wounded, against enemy losses of at least 128 and possibly another 192 killed, plus 95 prisoners and 122 weapons captured. The enemy had been unable to thwart any part of the brigade’s plan or to mount any sort of an attack on any brigade unit. The Viet Cong had been outfought and outsmarted at every turn.
Some of the Australians wanted to stay and complete the exploration of the tunnel complex, but General Westmoreland needed all the combat forces he had to sweep and secure other areas for soon-toarrive units. The victim of Washington armchair experts, he also was ordered by President Lyndon B. Johnson to cease offensive operations to observe the traditional truce for the Tet Lunar New Year.
On January 15, General Williamson went to Saigon to brief Secretary of State Dean Rusk and Ambassador-at-Large Averell Harriman, while senior 173rd officers attended a press conference in Saigon. The success of Operation Crimp was recorded in after-action reports and lessons learned, and in the memories of the veterans. What happened at MACV and in Saigon was well over the horizon as viewed from battalion level. The U.S. 25th Infantry Division moved into the Cu Chi area and had its own experiences in the war in the tunnels. More operations followed for the 173rd and by mid-1966 the original troopers completed their tour of duty, as did the Aussies in 1/RAR. The war went on. Operation followed operation. Crimp faded in memories.
So what happened to all those captured documents that identified the Viet Cong by name, occupation and street address throughout the Saigon region? The key leather satchel’s contents were translated and put together with all the other important information hauled out of the tunnels. MACV and South Vietnamese army (ARVN) order-of-battle staffs had an unprecedented wealth of information to add to their files on enemy units and on the entire Viet Cong organization. When MACV learned through the documents the advanced level of the enemy reconnaissance of American facilities in Saigon, it immediately reinforced security procedures and, on March 1, issued Counter-Intelligence Instruction No. 1.
Major General Joseph A. McChristian Jr., Westmoreland’s chief of intelligence, had visited the Australian unit during Operation Crimp. From the treasure of captured documents he realized just how serious the threat to Saigon was and initiated an intense program of enemy information collection in and around the capital. In mid-1966, MACV intelligence staff prepared a briefing on the situation. In contrast, the South Vietnamese had to be persuaded to do anything. It took months to push the issue through meetings, briefings and discussions with U.S. and Republic of Vietnam bureaucracies. It took nearly a year after the intelligence was uncovered for the December 1966 Operation Fairfax/Rang Dong to be launched—searching for the enemy in the Saigon region. The city itself, which was the responsibility of the South Vietnamese, was not included in the operation. As 1967 unfolded, the U.S. 199th Light Infantry Brigade operated in coordination with three ARVN battalions and achieved significant success on the outskirts and approaches to Saigon. Disappointingly, however, instead of the ARVN personnel improving in proficiency, they tended to leave everything to the Americans. After the operation was handed over to the ARVN in December 1967, Fairfax/Rang Dong became completely ineffective, allowing the Viet Cong to regenerate in time to mount their Tet Offensive in early 1968. Westmoreland would admit later in his memoirs that handing over responsibility for Saigon and its environs to the ARVN “made for uneasy moments.”
Most critical to the inability to exploit the massive tunnel intelligence, however, was the fact that there was no combined U.S.- ARVN office in January 1966. Throughout the war the South Vietnamese government retained ownership of all captured documents. ARVN units that captured documents up to 1966 held them, but made little effort to exploit the information. The South Vietnamese had to be persuaded to adopt sensible procedures, but could not be forced to do so. General McChristian persisted, but the combined document exploitation center did not open until October 1966, and the combined intelligence staff did not start functioning until the following month. The Saigon government retained responsibility for its own internal security matters, and therefore no concentrated follow-up action using the information from Crimp was taken by the South Vietnamese against the Viet Cong infrastructure in Saigon. Incredibly, the Viet Cong in Saigon continued their work barely interrupted by the government security forces. Westmoreland did not mention Operation Crimp in his 1968 end-of-tour report or 1976 memoirs. McChristian made no note of the operation in his monograph on military intelligence published in 1974.
Exactly a year after Crimp, in January 1967, Operation Cedar Falls was launched in the same area. But the Viet Cong in Saigon still only suffered pin-prick irritations from the government, and the Tet Offensive followed in 1968. I continue to believe that if the information gained from Operation Crimp had been used immediately to destroy or even simply dislocate the Viet Cong political infrastructure in Saigon in 1966, there could not have been a 1968 Tet Offensive because there would not have been the necessary planners and coordinators for the entire Saigon region. A widespread clandestine organization necessary to support an offensive on the scale of the Tet attacks requires years to recruit and train. There would have been no point in a 1968 Tet Offensive that did not include Saigon. If the enemy infrastructure in and around Saigon had been destroyed, then by early or mid-1967—with the North Vietnamese Army and Viet Cong defeated in every battle (as they were), with General Vo Nguyen Giap’s strategy in ruins and with U.S. air strikes ratcheting up pressure throughout North Vietnam and Laos—it is very likely that Hanoi would have been forced to cease its armed invasion of the South and possibly begin to negotiate from a position of weakness, as had happened in Korea. And South Vietnam might still exist today. In the tale that was Operation Crimp, it was as if the 173rd Airborne Brigade’s warriors went into the cave of the enemy dragon and captured the magic pearl—but the corrupt and incompetent local princes could not make use of its powerful secrets, and were thus eventually defeated by their enemies. What remains untarnished in this tragic tale, however, is the shining story of the warriors’ exploits.
Lex McAulay enlisted in the Australian Army in 1960 and graduated from the yearlong Vietnamese language course in 1963. He was aboard the first planeload of Royal Australian Regiment soldiers to Vietnam. He served three tours in Vietnam and retired from the army in 1982. For additional reading, see: Lex McAulay’s Blue Lanyard, Red Banner; and Sedgwick D. Tourison’s Talking With Victor Charlie.
Originally published in the October 2007 issue of Vietnam Magazine. To subscribe, click here.