The senior Viet Cong commander inside the Iron Triangle received word of Operations Cedar Falls as soon as the South Vietnamese did. When the incredulous John Paul Vann and the USAID were receiving the briefing from the II Corps staff on 7 January, the VC commander had made the decision not to fight. In less than 24 hours, five of his nine battalions had already escaped north toward Cambodia (they were out before the 1st ID hammer landed) or southeast through the Cu Chi tunnels toward Saigon. Two battalions attempted to escape west and were effectively destroyed by 2nd Brigade, the 25th Infantry Division. The other two battalions went into the extensive tunnel systems and either waited for the 11th ACR to pass overhead, or they fought it out in the numerous small unit actions over the next two weeks. Most casualties from the operation were the result of the booby traps and small ambushes, many inside the tunnels.

After the civilians of Ben Suc and the hamlets were evacuated, the Americans went after the tunnel system with a vengeance. American volunteers, called “tunnel rats”, delved downward and engaged the VC with pistols, knives, and flashlights. To their astonishment, they caught a glimpse of how deep and extensive the tunnels actually were, and the futility of trying to clear them. Tunnel Rats were not new in the war, but where before they were just volunteers with giant brass gonads, Cedar Falls was the first time they were specially trained and organized. When they deemed it impossible to go further, engineers above would flood the tunnels with acetylene gas, light it, then bull dozers would collapse the tunnels and seal them off. For good measure, B-52 strikes would be called on the more extensive and deeper systems to collapse them, which it was found out later was the only real way of damaging them permanently, and then only when the bombs fell directly above.

Operation Cedar Falls was a body blow to the VC. Publicly the Communists declared it failure, just as Saigon declared it a victory. But by the American’s own metrics it was not nearly what Seaman was hoping for: the body count was relatively low, just 753 or just under two battalions. 507 VC defected under the Chieu Hoi program, though many disappeared later. Thousands of tons of rice were seized but few weapons and ammunition. The big haul was intelligence, though Westmoreland couldn’t say that on the air. Over 500,000 documents and the majority of the COSVN headquarters support staff were captured (the “primaries” and the important members of the staff moved to the Fishhook in Cambodia in December. Cedar Falls interrupted the movement of the remainder). The new found intelligence painted a far different picture than what the Americans or South Vietnamese had thought to be true.

It took the first half of 1967 to translate and analyze the document and interrogation haul from Cedar Falls. And Westmoreland and Saigon couldn’t believe what they saw. The insurgency was so deeply entrenched that VC shadow governments operated alongside the South Vietnamese at every level. Many South Vietnamese Army units had truces with the VC in their districts. The documents painted a picture of an insurgency that was clearly winning, and whose district and provincial leadership were unafraid of having their names and activities recorded. The haul provided targeting fodder for thousands of Phoenix Program operations and quickly resulted in the expansion of CORDS. In the end the document dump probably sank Westmoreland. Although Westmoreland brilliantly saved Vietnam from being overrun in 65, and then miraculously built up the US conventional offensive presence nearly from scratch then fought Giap and Than to a standstill in 66, President Johnson and Secretary McNamara no longer believed what Westmoreland was feeding them. Even money says it led directly to the decision to replace him in late 1967.

The intelligence windfall was not lost on Giap. He was furious at Than and would hold it against him until his rival’s “accidental” death later in the year. Operation Cedar Falls proved that the VC in South Vietnam were not ready for main force operations against the Americans, though it would take another American operation to confirm it. Giap and Than wouldn’t have long to wait.
On 26 January 1967, just 18 days after LTC Haig and his battalion landed around Ben Suc, the last Americans and South Vietnamese pulled out of the Iron Triangle to prepare for the next corps level search and destroy operation. Despite the severe damage to the tunnel system and a dozen square miles of jungle defoliated, the first VC moved back in just ten days later; the first civilians, two weeks later.

The Iron Triangle would continue as a VC safe haven for another three years.

On 7 January 1967, ten battalions of 25th Infantry Division and 196th Infantry Brigade truck borne infantry established blocking positions along the Saigon River, and the next day six battalions of the 1st Infantry Division and 173rd Airborne Brigade air assaulted into landing zones north and east; all to establish a large cordon around the Iron Triangle and prevent the escape of the nine Viet Cong main force battalions suspected of operating from there.

The Iron Triangle was just one of the Viet Cong’s 80 plus relatively inaccessible safe havens inside South Vietnam in January 1967. It was 40 square miles of thick double canopy jungle, and few open areas inside. For over twenty years it was the center of Vietnamese resistance around Saigon: first against the Japanese, then the French, and now the Americans. Like Iwo Jima in the previous generation, the entire area was honeycombed with decades’ worth of tunnels, 30,000 miles worth, some extending four and five levels underground. The Triangle contained hospitals, communications centers, rest and recreation areas, logistics depots, way stations for communist units coming from Cambodia, a processing and training center for new VC recruits, and until recently the Central Office for South Vietnam, the VC main headquarters. The entire 6500 strong civilian population was organized to support the VC infrastructure. The South Vietnamese Army assaulted the area twice, once in 1963 and again in 1964, but after heavy fighting all they could do was blow up some tunnel entrances, and return to Saigon. In early 1966, the 173rd Airborne, 1st ID, and the Royal Australian Regiment tried again in Operation Crimp, and though they did more damage than the ARVN assaults, they did little more than dent the extensive fortifications and tunnel system.

In the spring of 1966, an American officer who was an ARVN advisor had dinner with Gen Westmoreland at his request. During the after dinner cigar, Westmoreland asked him what needed to be done about the Iron Triangle, as the advisor had been on the last two operations into the area. The young captain replied without hesitating, “Burn it down”. In August, Westmoreland attempted just that. The Air Force dropped defoliants on the area which dried the vegetation. And then two weeks later, they napalmed it. 15 of the 40 square miles of the Iron Triangle went up in flames, but it burned so large and so hot that it created a weather phenomenon known as a “cloudburst”, which eventually put the fires out. In any case, it didn’t matter – the jungle just grew back within a month when the monsoon hit later that year. The Americans hadn’t been back since.

LTG Seaman assured Westmoreland and DePuy that this time would be different. Once the Iron Triangle was occupied, and the VC defeated, the entire population would be relocated by the South Vietnamese, and two brigades of engineers would level the entire area and collapse the tunnels. Operation Cedar Falls would have five times the manpower as Operation Crimp. Also, the 2nd Brigade 1st Infantry Division and the entire 11th Armored Cavalry Regiment would serve as the hammer. The VC would not escape this overwhelming force, and they would not reoccupy the barren wasteland that would remain.

On the morning of 8 January 1967, the first M113 armored personnel carriers and M48 tanks of the 11th ACR crossed the Tinh River in the east and crashed through the jungle driving the VC forward like hunting dogs. Coming in low out of the rising sun, the 500 men of the 1st Battalion, 26th Infantry Regiment led by LTC Alexander Haig descended upon the village of Ben Suc, the administrative epicenter of the Iron Triangle, and the home of most of the population.

The surprise was complete, or so it seemed.

LTC Haig’s battalion quickly surrounded the village of Ben Suc, and less than dozen of the villagers fought back. Those who resisted were quickly overwhelmed. Loudspeakers broadcast for the villagers to assemble outside of the school and about 1000 showed up. A second wave of helicopters brought in a field kitchen and medical personnel, as well as an ARVN battalion to screen them and conduct an extensive search to the village. The Americans spread out into the surrounding jungle, or secured the entrances to the numerous tunnels they found.

The Americans were under strict orders that “Vietnamese deal with Vietnamese”. The American troops were supposed to fight the VC, and the ARVN deal with the population. Unfortunately, LTG Seaman’s desire for secrecy meant that the South Vietnamese, and even the advisors and USAID personnel weren’t told of Operation Cedar Falls until the day before it started. The VC were surprised, but the South Vietnamese were even more surprised. They were completely unprepared to secure such a large village, and screen the entire population. And then they had to transport the villagers, their possessions and livestock to a resettlement camp at the province capital at Phu Cuong down the Saigon River.

The ARVN troops found dozens of tunnel entrances and hundreds of hiding villagers. And they weren’t easy on them. Accompanying Haig’s battalion was a reporter, Jonathan Schell from the New Yorker, who chronicled everything he saw. And he saw a lot. One incident stood out. Schell walked into a hut and witnessed an ARVN soldier beating a suspected VC for information, in front of an American advisor. The bored looking advisor calmly explained to Schell that it was part of their culture, that they had “methods and practices” that Americans weren’t accustomed to, and he wasn’t here to impose American values on the South Vietnamese. (aka the wrong answer in “The COIN Culture Conundrum” i.e Pick one: A. Step in, stop the abuse, upset the supposedly “friendly natives”, and get yelled at later by the smug ones who think all cultures are equal and by stopping human rights abuses, whether it be abusing women, screwing little boys, or in this case beating prisoners, you are “interfering with their culture” or “imposing American Values”. Or B, Letting it happen thereby being more “Culturally sensitive” and then getting crushed for violating someone’s human rights. The right answer is always A, but you would be floored how many well-meaning people overlook gross violations of human rights in the name “cultural equivalence”.) Schell was rightfully appalled. His observations on the evacuation of the village, especially the beating, would be published in the New Yorker in July, and it would set the Summer of Love on fire.

By noon, the system was breaking down. 3500 villagers were gathered at the school. 106 were detained and helicoptered out for further interrogation, but the rest waited, and waited. They couldn’t return to their homes, and the South Vietnamese couldn’t get transportation coordinated to move them. Chaos began. And order was only maintained by force. The bad day turned into a worse night as the entire population, which would grow to 6000, were forced to stay by the school.

Shocked at the scene in the morning, Haig stepped in and took charge. He informed DePuy that he needed assistance, or a humanitarian disaster was going to ensue, if it hadn’t already. The furious DePuy organized an ad hoc truck convoy to transport the villagers. It would take them two days to transport everyone in convoys which the VC left unmolested for the most part. The original plan was to use a South Vietnamese Navy flotilla but DePuy had them transport the villagers possessions and livestock (which went as well as it sounded), because most of the villagers were gone by the time the boats were assembled.

The camp at Phu Cuong was not prepared either. As reports from the convoys came in, DePuy went down to see for himself and was shocked at what he found: it lacked adequate food, shelter, sanitation, medical facilities, even water. The enraged DePuy called the USAID director in Saigon, the equally livid John Paul Vann, a former advisor, ranger, LTC, and probably the most culturally competent American in Vietnam, and told him he was taking over the resettlement as well as the evacuation. (In Vann’s defense he only found out about Cedar Falls with the South Vietnamese, but with 6000 dejected, cold, hungry, and thirsty refugees in a field with nothing but the clothes they wore when the loudspeakers told them to go to the school, that hardly mattered)

The conventional American Army just got its first lesson in counterinsurgency in Vietnam: If not you, then who? Understaffed and underfunded civilian agencies? 12 man Special Forces teams? Random poorly trained, inexperienced indigenous troops crawling with infiltrators that you aren’t partnered with? The enemy?

Ben Suc sent shock waves through Saigon, Washington, and America

After Operation Attleboro, two nearly identical questions were being asked in both Hanoi and Saigon: should the military forces engage main force units, or should they conduct guerilla warfare (for the North Vietnamese and Viet Cong), or Counterinsurgency (for the US and South Vietnam)? This sparked vicious debates in both capitals.

In Hanoi, Giap, the NVA Commander, wanted to revert back to guerilla warfare after the horrible losses in 1966 suffered by the NVA and VC. Giap wanted to avoid the Americans, attack the South Vietnamese regime indirectly through the population (Classic Mao). Gen Nguyen Chi Than, the Central Office for South Vietnam or COSVN commander, wanted to continue engaging American units directly. Although Attleboro nearly destroyed the elite 9th VC Division, it did not. And furthermore its remnants could easily be reinforced from Cambodia. Thanh remarked that the 9th VC took the best that the Americans could deliver (an entire corps assault) and they still survived. The “soft” Americans by contrast were exhausted, and their casualties directly inflamed the burgeoning antiwar movement in the US. Also, the American casualties went a long way in proving the superiority of the Communist soldier vs the American/ARVN soldier to the population, and eventually gaining their support for an uprising in the South. Furthermore, the American main force units in conventional operations were practically VC recruiting tools with their disregard of the population. Thanh argued that Giap’s course would force the Americans to treat the people better, and avert a general uprising (He was right). Thanh won the argument.

In Saigon, the 1st ID Commander, MG DePuy, also wanted to continue engage main force units. He knew the 9th VC Div was not destroyed. But he could finish the job in the relatively underpopulated Tay Ninh province, an area that the NVA and VC must traverse to get to Saigon and the South from the Fishhook in Cambodia. His staff was already planning this follow up operation named Junction City, after Ft Riley’s ville. However, LTG Seaman, the II Corps commander, wanted first to clear the Iron Triangle, a VC stronghold south of Tay Ninh and just north of Saigon in a heavily fortified, nearly impenetrable forested area bordered by the Saigon river in the south and the Tinh River in the west. It was from there that devastating attacks were launched on targets in the city. Seaman wanted to isolate the Iron Triangle, destroy the VC infrastructure, capture the COSVN headquarters which intelligence placed there, and then focus on the population. However, since there weren’t troops available to hold the 160 square km area, his plan was to relocate the population to more easily defendable areas in conjunction with the CORDS “New Life Villages”. The area could then be turned into a free fire zone, defoliated, and rendered unusable by the VC.

They took the dispute to Gen Westmoreland, the MACV Commander. DePuy was one of Westmoreland’s golden children, so he thought Junction City was guaranteed. But surprisingly, Westmoreland deferred to Seaman. So Seaman postponed DePuy’s operation, and ordered his alternative to clear the Iron Triangle, an operation named after the hometown of a recent 1st ID Medal of Honor winner,

Cedar Falls.