The 40th anniversary of the end of the Vietnam War is a good time to take stock of the 20-year conflict, its justification, its cost in lives and dollars, and whether it was worth it.

A spate of documentaries — including “Last Days in Vietnam,” which was recently previewed at The Grand in Ellsworth — take a fresh look at the conflict. Some emphasize heroism and compassion. Others offer a harsher assessment of a conflict that killed more than 58,000 U.S. servicemen, more than half under the age of 21. Nearly 1,000 died on their first day in Vietnam.

“Last Days in Vietnam,” a PBS documentary scheduled to air on April 28, focuses on the successful effort of withdrawing American forces to evacuate thousands of South Vietnamese as communist North Vietnam took over Saigon and the rest of the country. Official policy was to bring out only U.S. servicepeople and their dependents and South Vietnamese helpers. Instead, a group of officials led by Ambassador Graham Martin, violating their orders, managed the evacuation of thousands of South Vietnamese by sneaking them onto ships and helicopters.

Many viewers felt the film neglected dark and controversial aspects of the war, such as the American carpet bombing campaign that killed thousand of Indochinese civilians and abuses by some of the South Vietnamese leaders supported by the United States.

PBS evidently saw that more was needed for a rounded picture of the Vietnam War. It has scheduled several other documentaries for the last few days before the April 30 anniversary. These include “My Lai,” about the slaughter of innocent Vietnamese villagers by a U.S. army unit; “The Draft,” about the lottery that put thousands of young Americans into the war; “Dick Cavett’s Vietnam,” about the television host’s debates covering all sides of the war; and “The Day the ’60s Died,” about the shooting death of four students in an anti-war protest at Kent State University, which ballooned into nationwide protests that helped destroy the Nixon administration.

The war was a follow-on from the French war intended to restore its Indochina colony. When the effort failed and the French withdrew, President John F. Kennedy carried on the conflict. Kennedy’s motives differed from the French territorial objective. The Kennedy administration, from the president down through the ranks, saw the intervention as a defensive act against international communism. The Kennedy approach also reflected a humanitarian effort to protect the South Vietnamese people from a communist takeover.

After the Kennedy assassination, President Lyndon B. Johnson expanded the war until a maximum of 536,000 U.S. troops were engaged in Vietnam in 1968.

The Congressional Research Service put the cost of the war at $111 billion — nearly one-third of the cost of World War II and three times the cost of the Korean War. The Armed Forces Ministry Museum in Largo, Florida, puts the deaths at 58,148, plus 75,000 severely disabled. It says that 61 percent of the dead were under the age of 21, including five 16-year-olds, and 997 were killed on their first day in Vietnam.

Estimates of Asian deaths in the Vietnam area vary widely. One set of figures includes 444,000 communist soldiers and 587,000 Vietnamese, Laotian and Cambodian civilians during the war. After the American withdrawal, between 1 million and 3 million Cambodians are widely believed to have been slaughtered, and hundreds of thousands of Vietnamese are said to have died fleeing from Hanoi’s rule.

The question of whether the war was worth the cost calls for a judgment on the main motivation for U.S. involvement. Our leaders saw the war as striking a blow against a threatening “sino-Soviet bloc.” The popular domino theory held that if one country came under communist domination others would follow and communism would rule the world. Actually, Russia and China were rivals and enemies. And Ho Chi Minh, the leader of North Vietnam, was seen by some to be more a nationalist than a communist. His often quoted slogan, “Nothing is more precious than independence and freedom,” has persuaded many.

Retired Defense Secretary Robert McNamara, in his 1995 book, “In Retrospect: The Tragedy and Lessons of Vietnam,” wrote that the United States policy was “terribly wrong, and we owe it to future generations to explain why.”

One possible way to ponder the 40th anniversary of the war’s end is to appreciate the fact that the conflict that so divided the nation has long been over. But it really isn’t over at all. Americans will always argue whether the United States was right in fighting — and losing — the Vietnam War.

Richard Dudman, who lives in Ellsworth, covered the Vietnam War for the St. Louis Post-Dispatch, where he worked from the 1950s to the 1980s. He is a former BDN contributing editor.