WESTMINSTER, Calif. — After the longest period of war in United States history, the Americans announced they were finally pulling out. Troops boarded jets and left. The White House pledged continued support for local allies, but appetite for the war had dried up at home, and soon so did funding.
“We wanted to fight, but no supplies, no fuel, no rockets. And the Americans did not help like they said they would,” Uc Van Nguyen said on a recent morning as he remembered the slide toward defeat. “I think in the end we felt betrayed.”
He was recalling the fall of the Republic of Vietnam in 1975. But Mr. Nguyen, who was a lieutenant colonel commanding a helicopter wing in the South Vietnamese Air Force, sees parallels today with the conflict in Afghanistan.
Like tens of thousands of other South Vietnamese veterans, Mr. Nguyen fled after the nation’s collapse. He now lives in suburban Orange County, Calif., after settling in Westminster, where nearly half of the residents are Vietnamese. In the Little Saigon neighborhood, the yellow and red flag of the Republic of Vietnam still flies above local stores and houses, and each year the city officially marks the date of the republic’s defeat, which they call “Black April.”
In a strip mall, veterans of the war and their children have put together a small museum — glass cases filled with medals and photos from a country that no longer exists. There, a few men, now gray with age, gathered recently to compare their experience with the news from Afghanistan.
All said they saw stark similarities between Vietnam 46 years ago and Afghanistan today: a swift pullout, an enemy defying peace deals, and an American-made military suddenly left with little support. They shook their heads in disappointment and cautioned that a similar collapse could be in the making.
In both conflicts, the brunt of the fighting fell on local forces. An estimated 250,000 South Vietnamese troops died in combat. In Afghanistan, figures hover near 70,000.
To be sure, the defeat of the Afghan government by the Taliban is anything but certain. And the quick collapse that swept Saigon, with American helicopters whisking desperate throngs from the roof of the United States embassy, may never come to Afghanistan’s capital, Kabul. President Biden met with the Afghan president, Ashraf Ghani, at the White House in June and vowed to provide $3.3 billion in security aid, saying, “We’re going to stick with you, and we’re going to do our best to see to it you have the tools you need.”
Mr. Nguyen, wearing a ball cap from his old military unit, said those words sounded too much like the promises his country was given.
“We never thought it could happen to us, never in your mind do you think you will lose your country,” Mr. Nguyen said. “But then it happens and there is no way to reverse it.”
At the beginning of the Vietnam War, when Mr. Nguyen was a cadet fresh out of his country’s military academy, the United States brought him to Texas, where the American military trained scores of Vietnamese officers to be pilots. For years he flew American-supplied helicopters side by side with American military advisers.
In 1973, as part of a peace deal the United States forged with Communist forces in North Vietnam, President Richard Nixon announced the withdrawal of all American troops from Vietnam. Just like in Afghanistan, the peace deal left out the local government, and allowed enemy forces to stay in place. Just like in Afghanistan, Nixon vowed to continue to support America’s ally financially. Congress, however, was in no mood. In 1974, it approved less than a third of the $1.6 billion the Defense Department requested for South Vietnam.
By the time Communist forces entered on Saigon, Mr. Nguyen had already cannibalized parts from several helicopters to keep a few flying and had ammunition for just one short mission. In the end, he commandeered a helicopter, took as many men as he could, and flew to safety in Thailand.
“I didn’t want to leave, but I had no choice,” he said, looking down at his hands. “Our government and our friends abandoned us. It was the worst chapter of my life.”
Ly Kai Binh was a gunnery sergeant in the South Vietnamese Marine Corps who for years fought alongside Americans. In the Afghans’ predicament, he recalls his own. In Vietnam, American advisers taught American tactics using American equipment, including expensive air support to cover fighters on the ground.
“They taught us to fight like rich men, even though we were living as poor men,” he said. “And after they left we had to ration bullets. We couldn’t afford to fight the way they taught us to.”
On the last day of the war, Mr. Ly was at an abandoned American base when he heard a radio report announcing the surrender.
“We cried, we cursed, it is hard to describe the hurt,” he said. He decided to keep fighting. He joined a guerrilla force in the countryside. He was eventually captured and taken to a concentration camp run by the new Communist government. After a year of hard labor he escaped and fled to the United States.
He hates the idea of abandoning another ally but also worries that committing to continuing a war may be folly. He wondered aloud whether Afghanistan’s American-built government could ever unite the country’s tribal culture in peace.
“I am an American citizen now,” he said. “I understand we have to protect our country’s interests. We have been at war so long. But still, we need to keep our promises. That was not done in Vietnam.” He sighed. “I don’t know if it can be done now.”
In Kabul this week the streets clattered with a semblance of normality, but the fate of the country was the topic of discussion on every corner. And lines at the city’s passport office had grown considerably larger. Afghanistan is starting to see budget cuts that echo Vietnam.
Afghan security forces are already feeling the American absence. With dwindling American air support, troops on the ground have lost their biggest tactical advantage and morale is faltering: Hundreds of Afghan troops have surrendered to the Taliban in recent days.
There are important differences between South Vietnam and Afghanistan, said Richard L. Armitage, who served three tours alongside Vietnamese commandos, and later served as deputy secretary of state during the invasion of Afghanistan. The North Vietnamese had tanks, artillery, an air force and a sophisticated supply line. The Taliban has little more than rocket launchers and a fleet of pickups.
But Mr. Armitage, who was present at the fall of Saigon and ended up leading a boatlift of more than 30,000 refugees, said there were also important similarities.
“In both cases you have a corrupt and ineffective government,” he said. “And the question is whether the military will be willing to fight for it, or just take off their uniforms and disappear.”
He warned that Kabul could fall quickly, and that there was still no workable plan in place to evacuate all the Afghans who aided the United States.
For a generation of American troops, watching the hard-won stability dissolve has been heart-wrenching. For Hugh Pham, who is the son of refugees from South Vietnam and deployed in 2012 as an intelligence officer working closely with Afghans, the echo of history is that much more painful.
The similarities between his relatives and the Afghans struck him on deployment when he ate watermelon with Afghan soldiers; they doused it with salt, just like his Vietnamese uncles had.
“I saw we were the same,” said Mr. Pham, who is a captain in the Army Reserves and now lives in Germany. “At that moment I made it my mission to try to vindicate my family’s past — to not let things fall apart again.”
Instead, he witnessed the same patterns, only now with the roles reversed. He was part of the American effort that expected the local forces to do more with less, and somehow establish peace in a place the United States never could.
In the end, Mr. Pham became resigned to save those he could, and worked to get a visa for an interpreter he worked closely with.
“I just wish we could have done more,” he said. “I wish we had found what the right way was.”
Thomas Gibbons-Neff contributed from Kabul.
Vietnamese Veterans See Echoes of US Betrayal in Afghanistan is written by Dave Philipps for www.nytimes.com