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This article was previously published in the CIA’s Studies in Intelligence.


Day la nhung tin tuc cua Tieng Noi Hué Ky phat thanh tu thu do Hoa Thinh Don.

That’s what I listened to every day, the Voice of America in Vietnamese. I listened to the BBC, I listened to the American Radio Service, I listened to anything I could hear to keep track of what was happening. It was April, 1975. I was in Saigon waiting for the North Vietnamese to attack.

As a speaker of Chinese, French, and Vietnamese, I’d been operating in Vietnam under cover on and off for thirteen years. My job was signals intelligence (SIGINT), the intercept and exploitation of the communications of the invading North Vietnamese. I was an employee of the National Security Agency, but my connection with NSA was classified; my name was redacted from unclassified NSA documents. Now, after forty years, my work has been declassified, and I can tell the story of what happened.

My final stint in Nam was in 1974 and 1975. I was as the head of the covert NSA operation in Saigon. I had two missions: to keep the U.S. Ambassador, Graham Martin, abreast of signals intelligence on the North Vietnamese, and to assist the government of the Republic of Vietnam (South Vietnam) in its own signals intelligence effort. Our suite of offices was in what had been the Military Assistance Command, Vietnam (MACV) building, by that time named the Defense Attaché Office or DAO building. The edifice was so huge we called it “Pentagon East.” It was located on the military side of Tan Son Nhat airport on the northern edge of Saigon in a compound that housed other buildings, several parking lots, tennis courts, and incinerators. That’s where I was when the North Vietnamese attacked us.

Meanwhile, my wife, my four children, and I lived in an elegant villa on Le van Duyet Street in the residential section of Saigon, near the presidential palace. That’s where they were when a disgruntled South Vietnamese pilot bombed the palace not long before the city fell.

Beginning of the End

For me, the story of the fall of Saigon begins in January, 1975, with the North Vietnamese army’s conquest of Phuoc Long Province, some 60 miles north of Saigon. SIGINT revealed that infiltration of men and matériel from North Vietnam had spiked since the autumn of 1974, always a signal that an offensive was coming, and other intelligence indicators of a forthcoming attempt to take Phuoc Long were unmistakable. Nevertheless, the surprise Communist victory was an unparalleled blow; it was the first time during the entire war that the North Vietnamese had captured and held a whole province, including the provincial capital.

As I learned later, North Vietnam was testing American resolve: would we Americans keep our solemn pledge to counterstrike if the North Vietnamese violated the cease fire signed in Paris in 1973? The seizure of Phuoc Long was a gross violation. We did nothing.

With a shift in the pit of my stomach, I went over our own evacuation strategy and assured myself that each of my men in the field—at Can Tho in the south, Pleiku in the highlands, and Da Nang in the north—was covered in the escape plans of the State Department consuls in those areas. I confirmed that I could reach each of our reps by both phone and radio if things went to pieces suddenly.

By the end of February, it was clear that the focus of the next North Vietnamese campaign was to be in the northern half of the country, the highlands and I Corps. Communist units in both areas were on the move.

On 9 March, I flew north with my counterpart, a South Vietnamese general, on his C-47 to Phu Bai, near Hué in the far north; to Pleiku in the central highlands; and thence to Ban Me Thuot in the southern reach of the highlands. Our purpose was to visit units under the general’s command to prepare them for the coming onslaught. In Pleiku, during a courtesy call with the commander of II Corps, Major General Pham Van Phu, things turned sour. The general I was traveling with and the II Corps intelligence staff chief tried to persuade General Phu that Ban Me Thuot would be the first target of the Communist campaign in the highlands. Intercept of North Vietnamese communications made that clear. The II Corps Commander was unpersuaded. He doubted that the Communists were preparing to strike, and if they were, II Corps headquarters would be the logical focus of the offensive. After all, he was the most important man in the highlands, and he was at II Corps headquarters in Pleiku.

My counterpart cut short our trip, and we flew directly, that afternoon, to Ban Me Thuot.

The first barrages against Ban Me Thuot had been launched that morning. Not long after we landed, while the general was inspecting his troops, I watched a battle erupt in the valley to the west of the ridge where the airstrip was located. We took off for Saigon just as the runway came under fire.

Ban Me Thuot fell within days, and South Vietnamese President Nguyen van Thieu ordered the evacuation of the highlands, starting on 15 March. The result was mass chaos as the military and the civilian population panicked and fled. All major roads to the coast were by then under the control of the North Vietnamese; fleeing military and civilians clogged the only open road, Route 7B, a secondary bypass, barely more than a trail in places, while the North Vietnamese repeatedly attacked them.

Route 7B came to be called “The Trail of Blood and Tears.” Something like eighteen thousand South Vietnamese troops were killed or captured; losses among civilians were over a hundred thousand. The highlands fell within the week.

Almost at once, I Corps, the northern five provinces of South Vietnam, crumbled. Eighty thousand refugees jammed the roads and ports, vainly trying to escape the Communists.

With the northern half of the country now captured, Communist forces moved south toward Saigon. I knew capitulation was weeks away.

To reduce the number of in-country people I was responsible for, I considered sending out some personnel, including my secretary, on the first OPERATION BABYLIFT flight on 4 April. The project, launched by President Ford, was an effort to save as many orphans (mostly Amerasian) as possible because we knew how vicious the North Vietnamese would be to the half-American, half-Vietnamese children. The adults onboard the aircraft, all volunteers, would act as caretakers for the children. By the grace of God, I decided against sending any of my people on the flight.

The C-5A Galaxy transport, the largest plane I’ve ever seen, was filled with orphans en route to California. It crashed shortly after takeoff killing 138. Among them were 78 children and 35 DAO folks. Each of us knew somebody who died in the crash.

The day after the C-5A disaster, I took my wife to lunch at the American Officers’ Club to break the news to her that she and our four children must leave the country immediately. She was incredulous. Just that morning she’d gone to a coffee at the embassy. Officials in attendance had advised the gathering to disregard news reports; we were all safe and had nothing to fear. Unpersuaded by my urging, she finally agreed to go on three conditions: she could choose the flight date, she and the children could tour the world on the way back to the states, and she could buy a new Buick station wagon as soon as she got home.

I disguised my family’s departure to look like a vacation in Bangkok (the Ambassador forbade evacuations—more about that later) and got tickets for them to fly out on 9 April. On the 8th, renegade a South Vietnamese air force pilot bombed the presidential palace, close to our house. My wife was now convinced, but because of the 24-hour curfew imposed by the South Vietnamese government in the wake of the air strike, I had to pull rank to drive my family through the multiple roadblocks in Saigon to the airport at Tan Son Nhat. But at last, I got them all on a plane headed for Bangkok. My relief to have them safe cemented my determination for what I had to do next.

Unsure how long I’d be able to get through the mobs of refugees swarming Saigon, I moved to my office at Tan Son Nhat and stayed there 24 hours a day, sleeping on a cot between the two flags next to my desk—the stars and stripes and the flag of the Republic of Vietnam—a .38 revolver under my pillow.

On 17 April, I was in my office, which was now doubled as my bedroom and stoveless kitchen, reading the latest messages and reports before I burnbagged them when one of my comms guys came in with a news dispatch—he wanted me to see it right away: Phnom Penh, the capital of Cambodia, had fallen to the Khmer Rouge, the Cambodian Communists. Within days we were reading grisly descriptions of the beheadings of Cambodian officials. I learned what terror tasted like.

C-130 hit next to my office

Getting Everybody Out

Since the middle of March, my principal concern had been seeing to it that none of my people was killed or wounded in the forthcoming attack. I had 43 American men working for me and I was responsible for the safety of their 22 dependents, wives and children, living in Saigon. My men in Da Nang, Can Tho, and Pleiku all managed to reach Saigon after hair-raising escapes and were working in our Tan Son Nhat office. I wanted to get all my people out now.

But Ambassador Martin refused to consider evacuations. On the one hand, he wished to avoid doing anything that might stampede the South Vietnamese; on the other, he genuinely believed that the prospect of the Communist flag flying over Saigon was unthinkable.

I was stymied.

My state-side boss, General Lew Allen, the Director of NSA, ordered me to close down the operation and get everyone out before somebody got killed, but the Ambassador wouldn’t hear of it. I made him a proposition: if he would let my people go, I would stay in Saigon until the end with a skeleton staff to assure that the flow of SIGINT reports for him from NSA would continue. He turned me down.

So I cheated. I sent employees and their families out any way I could think of. Some I had to order out—they were unwilling to leave me behind. Some went on trumped-up early home leave, some on contrived vacations. Others I sent out on phony business travel. One day toward the end, I bought a guy a ticket with my own money and, with no authorization and no orders, I put him in a Pan Am flight to the U.S. It was the last Pan Am flight from Saigon.

I knew I’d have to stay until the end. The Ambassador wouldn’t allow me to go, but, more important, I had to be sure all my subordinates and their families escaped. Besides, some 2700 South Vietnamese military personnel had worked with NSA for years. I was determined to do everything possible to get them out of the country before the North Vietnamese took Saigon. I knew how cruel the North Vietnamese would be to them if they could get their hands on them.

Since I couldn’t leave, I asked for two volunteers to stay with me. I needed a communicator and a communications maintenance technician to keep comms open to the U.S. Some men pleaded that they owed it to their wives and children not to risk their lives. I found that eminently reasonable. Then two brave men stepped forward: Bob Hartley, a communicator, and Gary Hickman, a maintenance man. I warned them of the danger and told them that they’d have to keep the equipment going through unforeseen emergencies that might include electrical outages and shelling.

They understood.

Even today I admire, no, love, those two men for their raw courage. They risked their lives because I asked them to.

On 21 April, Xuan Loc, 40 miles northeast of us, fell ending a heroic defense by the South Vietnamese 18th Infantry Division. Communist forces encircled us.

I instructed my comms center to reduce to the minimum the number of copies it made of each new incoming message. We bagged documents as soon as we read them and burned them in the incinerator in the DAO parking lot. I turned my full attention to persuading the Ambassador that the remaining Americans and the Vietnamese who had worked with us had to leave Saigon before we were captured or killed. In that task, to my undying regret, I failed.

The Last Week

On 22 April, the U.S. Defense Intelligence Agency estimated that the Republic of Vietnam wouldn’t last more than a week. It was comforting to see that the Department of Defense and Commander-in-Chief, Pacific harbored no delusions about what was happening in Vietnam, but the Ambassador was not in their chain of command. He reported to the Secretary of State and the President. Unless they overruled him, he still had the power to keep us all in Saigon. He convinced them no evacuation was necessary.

Despite the Ambassador’s refusal to call for an evacuation, outgoing commercial airlines were choked with passengers, and U.S. Air Force C-130 and C-141 transports daily carted hundreds of Vietnamese and Americans out of the country. The embassy made a point of explaining that their departure was not an evacuation. It was a reduction in force to free up resources to help the Republic of Vietnam.

I didn’t know how much longer I’d be able to get out and about—the crowds in the streets were becoming larger and more menacing. Some of the men, in ragged Republic of Vietnam military uniforms, were armed. I knew the danger, but several trips were crucial. I told my Vietnamese driver, who usually ferried me around town, to use his U.S. pass to drive his family onto the military side of Tan Son Nhat in the black sedan assigned to me, a Ford Galaxy with diplomatic plates and American flags, and escape while they still could. Then I took over the sedan. Armed with my .38, I drove it rather than my small Japanese car, foolishly believing that the impressive official vehicle would ward off the massed refugees.

I had it exactly backwards.

The sedan attracted the most desperate of those seeking evacuation. I was mobbed once, but when I bared my teeth and leveled the .38, the crowd pulled back just enough for me to make my way through.

One trek was to help a Vietnamese family related to our house servants to get into the air base at Tan Son Nhat so that they could find a way out of the country via a departing U.S. military aircraft. Because South Vietnamese guards at the gates would allow no one to pass without official identification, the family members hid in the trunk and on the floor by the back seat of the sedan, covered with blankets. The guard admitted me without incident. The family managed to get on a C-130 and fly to Guam. Much later, they contacted me in the states to thank me.

I risked another trip to check on a South Vietnamese officer I worked with. I wanted to be sure he and his troops knew where to go when the evacuation order was given, something I couldn’t discuss on an unsecured phone line. Always a model of Asian politeness, he invited me in and served me tea. He told me that his wife, who worked for USAID, had been offered the opportunity to leave the country with her family. That included him. But he wouldn’t go because he was unwilling to abandon his troops—no evacuation order had been issued—and she wouldn’t leave without him. Alarmed, I asked him what he would do if he was still in Saigon when Communists tanks rolled through the streets. He told me he couldn’t live under the Communists. “I will shoot my three children, then I will shoot my wife, then I will shoot myself.”

He didn’t escape at the end, and I have no doubt that he carried out his plan; many other South Vietnamese officers did precisely what he described.

That left one more requisite foray. I got through the hordes to the embassy and pleaded with the Ambassador to evacuate everybody as soon as possible, citing signals intelligence evidence that an assault was imminent. I repeated what I had already reported to him, that Saigon was surrounded by sixteen to eighteen North Vietnamese divisions, poised to strike. Communist troops less than two kilometers north of my office at the airport were awaiting the command to attack.

The Ambassador put his arm around my shoulder and guided me to the door. “Young man, when you’re older, you’ll understand these things better.” He showed me out.

Frantic, I went down the hall to the office of the CIA Chief of Station, Tom Polgar. He laughed at my frenzy and showed me a cable to Washington the Ambassador had released that morning. It stated that the signals intelligence evidence of a forthcoming assault could be disregarded. It was all due to the Communists’ skillful use of “communications deception.” Stunned, I asked Tom what evidence he had of communications deception. He waved my question away and bet me a bottle of champagne, chateau and vintage of my choice, that he and I would both still be in Saigon a year hence, still at our desks, still doing business as usual.

Even though I ran into him months later in the U.S., he never made good on that bet.

I finally understood what was going on. The embassy was a victim of what sociologists now call groupthink syndrome—firm ideology, immune to fact, shared by all members of a coterie. The Ambassador, and therefore his subordinates, could not countenance the prospect of a Communist South Vietnam and therefore dismissed evidence of the coming disaster. Graham Martin later told Congress he had been advised by the Hungarian member of the International Commission of Control and Supervision, the ICCS, that the North Vietnamese had no intention of conquering Saigon; they wished to form a coalition government with “patriotic forces in the south.” This from a representative of a Communist government allied to North Vietnam. And the Ambassador believed him in the face of overwhelming signals intelligence that the attack was at hand.Tom Glenn Vietnam highlands 1967

On 24 April, the wire services, which we monitored, reported a speech that President Ford had given the previous day at Tulane. He referred to Vietnam as “a war that is finished.” My cynicism overcame my dread. If the war was finished, what was I, a civilian signals intelligence officer and potential prisoner of singular value to the Communists—in short, a spy—doing in a combat zone with nothing better than a .38 revolver to defend myself against eighteen North Vietnamese divisions?

During the night of 26 April, I was trying unsuccessfully to sleep when a blast threw me from my cot and slammed me to the floor. I ran to the comms center. The guys looked dazed but everything was working and nobody was hurt. A bulletin arrived within minutes telling us that North Vietnamese sappers had blown up the ammo dump at Bien Hoa, just north of us. That meant, among other things, that panic in the streets would ramp up a couple of notches.

I started doing regular physical recons of the DAO building. Sometimes I took out a load of burnbags to the incinerator in the parking lot and burned them; other times I just wandered around. I wanted to be sure I knew beforehand if the North Vietnamese were going to breach the perimeter fence. As I walked the halls and crisscrossed the compound, I saw brawny young American men with skinhead haircuts who had appeared out of nowhere. They were dressed in tank tops or tee-shirts, shorts, and tennis shoes. When two or three walked together, they fell into step, as if marching.

Marines in mufti! I knew all the Marines in country, and I didn’t recognize any of these guys. What the hell was going on?

I found out that night. I was trying to grab a little sleep in my office. The door chime sounded. I grasped my .38 and went to the door. Through the peep hole I saw a middle-aged red-haired American man in a neon Hawaiian shirt, shorts, and rubber flip-flops. He gave me a flat-handed wave and a silly grin. It was Colonel Al Gray, a Marine officer I’d worked with over the years in Vietnam. I’d never before seen Al out of uniform—I didn’t think he owned any civies—and I knew he made it an iron-clad rule never to spend more than 24 hours in Saigon—his work was with his troops in the field and he disliked bureaucracy. I lowered the .38 and opened the door. “Hi,” he said. “Can I come in?”

In my office, I told him everything I knew about the military situation, but he knew more than I did. What he didn’t know in detail was what was going on with the friendlies. I told him about the unruly, desperate crowds jamming the streets and now ten to fifteen people deep outside the perimeter fence of our compound and my worry that the fence might not hold. He explained to me that he’d been named the Ground Security Officer—the man in charge—for the evacuation of Saigon once it was ordered.

But the Ambassador was doing everything he could to throw roadblocks in Al’s way. He wouldn’t allow Al’s Marines to dress in uniform, fly their own helicopters into the country, or stay overnight. So Al and his troops, in civilian clothes, had to fly in and out each day from the 7th Fleet, cruising in the South China Sea, via Air America slicks, the little Hueys, the UH-1 choppers that could only carry eight to fourteen people.

It didn’t matter. Ambassador or no Ambassador, the Marines had landed. They’d be ready for the evacuation the instant it was ordered.

During my next daylight recon of the compound, I saw 55-gallon drums ranged along the perimeter fence. I asked one of Al’s buzz cuts why they were there. He said the drums were filled with combustible material, probably gasoline, and wired: if the North Vietnamese penetrated the perimeter, the barrels would be detonated to wipe them out.

Another tour of the parking lot took me into a surreal world. Marines and civilians were cramming cars, my small white sedan among them, onto the side of the building by driving them into one another so that they formed a compacted mass. That done, the drivers turned their attention to the half-dozen cars still in the parking lot, large black sedans (including mine) and one jeep. These they used as ramming devices, crushing the heap of cars more tightly together. Then they turned the now-mangled sedans on the tennis courts. Again and again, they backed their vehicles to the perimeter and burned rubber to smash into the poles holding the fence around the courts until they tore out of the pavement. Next they used the cars as battering rams, flattening the nets and court fencing against the building. Lastly, they ground the vehicles they were driving into the jumble of mashed automobiles. The area between the fence and the wall of the building was now clear.

It dawned on me what was going on. The small Air America slicks had been able to get into and out of the compound one at a time, without hitting parked cars or the tennis courts, but the much larger Marine CH-53’s—each could carry 55 troops loaded for combat—needed more unobstructed space, especially if two or three were in the compound at the same time. One more obstacle to our escape had been removed.

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