By Clyde Haberman, New York Times

The Vietnam War ended in 1975. It did for Americans anyway. Not so for the Vietnamese.

Since 1975, more than 40,000 Vietnamese are believed to have been killed and about 60,000 others maimed by what is known as unexploded ordnance — land mines, artillery shells, cluster bombs and the like that failed to detonate decades ago. Quang Tri province alone, along the border that once divided Vietnam into North and South, is said to have been more heavily bombed than all of Germany was in World War II.

Unexploded yet active remains of the Vietnam War now lie in wait for incautious scrap-metal scavengers or for unsuspecting children at play. They are Vietnamese like Ho Van Lai. He was 10 years old in August 2000 when he and two cousins happened upon remnants of a cluster bomb. One of the cousins accidentally set it off, and was killed. Lai, now 26, was luckier, if losing both legs and much of his right arm can qualify as good fortune.

“I imagined that I would become a useless person,” he said when interviewed in Da Nang by Retro Report, a series of video documentaries exploring how major news stories of old shape modern events. “I was supposed to be living in peace,” Lai said. “Yet I was entangled with the war.”

The video focuses on Vietnam, but unexploded ordnance is a worldwide concern, from the detritus of long-ago combat to the armaments of modern battlegrounds like Afghanistan, Syria, Yemen, Iraq and Ukraine. Bombs and artillery shells from the two world wars still turn up in Belgium, England and France. By some estimates, 100 million or more anti-personnel land mines remain strewn across the globe, lurking as menaces.

“Land mines, in many senses, are the perfect soldier,” said Paul Heslop, director of programs for the U.N. Mine Action Service. “They don’t go to sleep. They don’t need to rest. You plant them and you arm them, and they will last for 20, 30, 40, 50 years.”

It could be argued that the danger, while ever-present, is less dire than it once was, thanks to global accords to rein in the weaponry. In 2014, the last year with available statistics, there were 3,678 known casualties from various types of old ordnance, as recorded by the Landmine and Cluster Munition Monitor, a tracking organization. The 2014 figure was 12 percent higher than the previous year’s, but it was well below the 9,220 dead and wounded in 1999.

That was when a mine ban treaty went into effect. It had been adopted in 1997 — in part, as the video notes, the product of a well-publicized campaign by Princess Diana, who was killed that year in a car crash in Paris. In 2008, a comparable treaty to outlaw cluster munitions was approved, taking effect in 2010.

Cluster bombs, a reality of war since the 1940s, are singularly nasty. One of them can contain dozens, even hundreds, of baseball-size “bomblets.” When the mother bomb opens, its bomblets are sprayed in all directions, tearing apart whatever is in their paths.

There are no time limits to their destructive abilities. If they fail to explode right away, they can remain active for years, lying on the ground and potentially lethal to unwary civilians. All too often, the victims are children drawn to these intriguing objects, as Ho Van Lai and his cousins were. Despite the decline in the toll since the 1990s, lingering ordnance continues to kill or maim an average of 10 people a day.

Thus far, 162 nations have joined the land mine treaty and 119 the ban on cluster munitions. But the nonsigners are some of modern warfare’s most formidable players, including China, Iran, Israel, North Korea, Russia, Saudi Arabia and the United States.

U.S. officials have defended their nonparticipation as an act of prudence. In 2008, a State Department spokesman said that “cluster munitions have demonstrated military utility, and their elimination from U.S. stockpiles would put the lives of our soldiers and those of our coalition partners at risk.”

As for land mines, the Pentagon describes them as especially helpful in the demilitarized zone separating North and South Korea. Critics say that mining that area is a pointless vestige of the Cold War. But U.S. military strategists regard the explosives as a useful first-line defense against a possible North Korean invasion of the South.

That said, the treaties have plainly had an effect even on the Americans. Land mines are so stigmatized that the United States has barely used them since the Persian Gulf War of 1991. Its stockpile, estimated at 3 million mines, is diminished.

President Barack Obama’s administration has also signaled a willingness to sign the anti-mine treaty (not that any action seems likely before the clock runs out on his term). In early September, Obama visited Laos, which U.S. forces secretly, and heavily, bombed during the Vietnam War. He pledged to double U.S. support, to $90 million over the next three years, to help Laotians find and dismantle active explosives buried in fields and forests.

The United States’ reliance on cluster munitions has also waned, having peaked in 2003 in the early days of the Iraq War. Military spokesmen say none have been used in the air war against the Islamic State in Syria and Iraq.

Although the United States continues to export these munitions, it attaches a requirement that they not be used in civilian areas, and they must be designed to explode in short order or else self-destruct. By the end of 2018, manufacturers will have to ensure that the failure rate for bomblet explosions does not exceed 1 percent, thereby reducing the potential future risk to civilians.

All the same, the world is obviously not at peace. The Landmine and Cluster Munitions Monitor identifies 57 countries as threatened by mines. Russia is suspected of having dropped cluster bombs in Syria. Saudi Arabia has used U.S.-supplied cluster munitions in Yemen, including in civilian areas. Anti-government forces resort to roadside bombs in countries like Afghanistan, Colombia, Iraq, Libya, Myanmar and Ukraine.

Vietnam stands as an example of the difficult future that may await them all if ever the guns are silenced. Chuck Searcy knows a lot about that. Searcy was a U.S. intelligence officer in Vietnam in the 1960s. He is now an adviser to Vietnamese who as part of Project Renew are cleaning up unexploded ordnance and helping victims like Lai.

“This was our responsibility,” he said, referring to the U.S. military. “We had created the problem.”

By some reckonings, it could take another century to complete the mop-up.

Countries around the world that are now in conflict, Searcy said, will “face the same problem 20 or 30, 40 years from now that Vietnam is facing.”

To Learn More:

While U.S. Drags Feet on Curtailment of Cluster Bombs, Their Use Goes Unabated in Yemen and Syria (by Sewell Chan, New York Times)

Army Claims it’s too Dangerous to Clean Up Radioactive Weapons Test Site in Indiana (by Noel Brinkerhoff and Danny Biederman, AllGov)

Obama Administration Agrees to Get Rid of Landmines…Except in Korea (by Noel Brinkerhoff, AllGov)

Two-Thirds of Senate Ready to Ban Land Mines; But Not Obama (by Noel Brinkerhoff, AllGov)

Obama Refuses to Sign Landmine Treaty (by Noel Brinkerhoff, AllGov)

Norway Sells All Shares in US Maker of Cluster Bombs (AllGov)