The Obama administration earned mild praise from arms control advocates — and scorn from its critics — when officials announced last week that the U.S. would no longer buy deadly anti-personnel land mines.

Long before the announcement, however, the Department of Defense was discreetly destroying portions of its land mine stockpiles, including a cache at Anniston Army Depot, where nearly 126,000 mines remain.

"We do demilitarization at all our facilities," said Justine Barati, a spokeswoman for Defense Department's Joint Munitions Command, which manages the nation's military ammunition plants. The military has destroyed 634,206 landmines at storage sites worldwide in the past 10 years, Barati said.

For decades, activists have called on the United States to completely swear off the use of antipersonnel mines — land mines that are designed specifically to kill or maim human beings, as opposed to stopping tanks or other large vehicles.

The problem with the mines, arms control advocates say, is that they linger on the battlefield for years, often killing non-combatants long after a war is over. The mines maim or kill an estimated 4,000 people every year, according to the International Campaign to Ban Landmines.

Since 1997, 161 countries have signed a treaty, known as the Ottawa Convention, which bans the stockpiling and use of the mines. The world's three biggest military spenders — the United States, Russia and China — have yet to sign the treaty. U.S. officials have long maintained that the mines are still needed to protect South Korea against a potential North Korean invasion.

That stance appeared to soften on Friday when a U.S. ambassador announced, at an international conference, that the Department of Defense would no longer make or buy antipersonnel mines. A Pentagon spokesman later said the land mine stockpile would begin to deteriorate in about 10 years, becoming completely useless 10 years after that.

"The United States is diligently pursuing solutions that would be compliant with and that would ultimately allow the United States to accede to the Ottawa Convention," the White House announced in a Friday statement.

Land mine critics welcomed the news, but they're still trying to make sense of some portions of the Friday announcement, which included a reference to 3 million mines in the U.S. stockpile.

"The previous independent research indicated that the U.S. has a stockpile of 10 million land mines," said Daryl Kimball, director of the Washington D.C.-based Arms Control Association. Kimball said the reason for the difference in numbers wasn't immediately clear.

In an emailed response to The Anniston Star, Navy Cmdr. Amy Derrick-Frost said the U.S. maintains a stockpile of about 3 million self-destructing mines.

Also known as "smart" mines, self-destructing mines are designed to deactivate or self-destruct after a certain period of time, minimizing their ability to kill civilians after a war. Derrick-Frost said the U.S. completely phased out the use of older, "dumb" mines by 2010.

"There are still some dumb mines in an inactive status that are waiting to be demilitarized," Derrick-Frost wrote.

Pentagon officials are tight-lipped about where mines are stockpiled. Derrick-Frost would say only that they are "in various locations worldwide, positioned to meet operational requirements."

Barati, the Joint Munitions Command official, said Anniston Army Depot now has 125,985 antipersonnel mines in stock. That number, she said, comes with a caveat.

"The number depends on what you count as an anti-personnel mine," Barati said. She said that by some definitions, the number of anti-personnel mines in stock could be higher.

Barati said she wasn't sure what types of mines are in stock in Anniston, though she did give The Star some Department of Defense identification numbers for the types of mines in the Anniston stockpile.

According to a website maintained by the arms-policy group Federation of American Scientists, those ID numbers match certain types of "scatterable mines" which can be spread across a battlefield via artillery rounds.

Among its other roles, Anniston Army Depot has long been a repository of weapons the U.S. is reluctant to acknowledge and unable to use. For decades, the installation stored M55 rockets, armed with chemical weapons, that began leaking within years of their manufacture. The rockets were among millions of pounds of chemical munitions — including several thousand land mines armed with nerve gas — that were destroyed in a chemical weapons incinerator between 2003 and 2011.

The U.S. hasn't used mines on a significant scale since the 1991 Gulf War, according to Kimball.

A 2002 report from the General Accounting Office concluded that all the antipersonnel mines used by the U.S. in the Gulf War were smart mines. The GAO found that 81 American troops were injured or killed by land mines during that war. It was impossible to say whether any of those soldiers were killed by U.S. mines, the report said, because Pentagon records classified the mines it encountered as either of Iraqi or unknown origin.

Commanders in the Gulf War expressed reluctance to use the mines, according to the GAO report, because of the possibility they would kill U.S. troops and restrict the mobility of forces on the ground. Still, 118,000 mines were deployed in the war.

Critics of the Obama administration, including the editorial page of the Wall Street Journal, have taken the administration to task for declining to buy new landmines when the Pentagon has yet to find a technology to replace the mines.

Kimball, the arms-control advocate, said last week's announcement isn't as significant as it sounds. The Pentagon stopped buying new mines in the late 1990s, he said, but until last week's announcement, the U.S. held open the door to possible future purchases of smart mines.

Kimball said the Pentagon's timetable, in which the current mine stockpile is expected to begin deteriorating in 10 years, is probably based on the shelf life of smart mines.

"These things require batteries," he said. "Batteries have a limited life."

Derrick-Frost, the Pentagon spokeswoman, said that while most dumb mines are awaiting destruction, the military uses a small number of them in counter-mine training.

Anniston once seemed poised to become a training center for civilians hoping to do de-mining work. In 1998, officials from the human-rights group Refugees International visited the city with a plan to convert part of the former Fort McClellan into a mine-training facility.

At the time, the group said Anniston's hot, wet climate and the hilly topography of the base were relatively close matches to conditions in former war zones such as Cambodia. City officials expressed hope that the center would come up with better ways to remove the explosives left behind in those hills by decades of military training at the fort.

The center was never built — not in Anniston, nor anywhere. Michael Boyce, the current spokesman for Refugees International, said it wasn't immediately clear why the proposal failed. The group did set up a separate nonprofit to start the demining center, he said.

"This entity did exist legally," he said. "It no longer exists."

Capitol & statewide reporter Tim Lockette: 256-294-4193. On Twitter @TLockette_Star.