– The armored trucks, televisions, ice cream scoops and nearly everything else shipped here for America’s war against the Taliban are now part of the world’s biggest garage sale. Every week, as the U.S. troop drawdown accelerates, the United States is selling 12 million to 14 million pounds of its equipment on the Afghan market.

Returning that gear to the United States from a landlocked country halfway around the world would be prohibitively expensive, according to U.S. officials. Instead, they’re leaving behind $7 billion worth of supplies, a would-be boon to the fragile Afghan economy.

But there’s one catch: The equipment is being destroyed before it’s offered to the Afghan people — to ensure that treadmills, air conditioning units and other rudimentary appliances aren’t used to make roadside bombs.

“Many nonmilitary items have timing equipment or other components in them that can pose a threat. For example, timers can be attached to explosives. Treadmills, stationary bikes, many household appliances and devices, et cetera, have ­timers,” said Michelle McCaskill, a spokesman for the Pentagon’s Defense Logistics Agency.

That policy has ­produced more scrap metal than Afghanistan has ever seen. It has also led to frustration among Afghans, who feel as if they’re being robbed of such items as flat-panel ­televisions and armored vehicles that they could use or sell — no small thing in a country where the average annual income hovers at just over $500.

The scrap yard outside Bagram Air Field looks like a postindustrial landfill in the middle of the Afghan ­desert, a surreal outcropping of mangled metal and plastic. There’s a tower of treadmills 50 feet high and an acre of American buses, trucks and vans, stripped of seats and engines. An ambulance is perched unsteadily atop a pile of scrap, like it fell from the sky. A mountain of air conditioning units sits next to a mountain of truck axles.

Some of the scrap still shows signs of its previous owners — vehicles spray-painted with American names, mattresses sunken from 12 years of use, bumper stickers from Hawaii or ­Oklahoma.

When U.S. officials first began planning for their exit, the idea was to ship home the majority of their equipment, especially expensive ­military gear like mine-resistant vehicles. That calculus has changed.

The Pentagon has budgeted the $5 billion to $7 ­billion to ship gear back to the United States. But that sum isn’t enough to take ­everything currently in Afghanistan.

Wanting at least a small return on their investment, the U.S. military decided to sell the leftovers for pennies on the pound. The United States has not publicly explained before why its gear is destroyed before being sold. U.S. officials are quick to point out that the Afghan government typically has an opportunity to express interest in American military equipment, which is sometimes handed over intact.