KABUL, Afghanistan - It could take years and possibly even a peace settlement for Afghanistan to reap profits from nearly $1 trillion in mineral resources that U.S. geologists say lie beneath its rugged terrain - some in areas now controlled by Taliban insurgents or warlords.

Geologists have known for decades that Afghanistan has vast mineral wealth, but a U.S. Defense Department briefing this week put the startling price tag on the country's reserves of iron, copper, cobalt, gold, and other prized minerals.

If impoverished Afghanistan is seen as having a bright economic future, that could help foreign governments persuade their war-fatigued publics that securing the country is worth the fight and loss of troops. It also could give Afghans hope, U.S. officials say.

Afghans are "developing an understanding that they have a source of indigenous wealth that if properly developed will enable them to be sovereign," said Paul Brinkley, a senior defense official who led the study.

Still, without increased security and massive investment to mine and transport the minerals, it could take years for Afghanistan to bank the rewards. And there's always the potential that such a discovery could bring unintended consequences, including corruption and civil war.

If the Afghan government has taken notice of the billions in potential revenue, so will the Taliban.

"Obama's war just became more important and more complicated at the same time," said Bruce Riedel, a former CIA officer who helped advise the administration last year when it was rethinking its Afghanistan strategy.

Riedel said that if the United States could provide the Afghans security and logistics to build up its mining capacity, Afghanistan's international stock would suddenly become more valuable. But there are a host of complications - competing industries and countries, corruption and war.

Stephanie Sanok, who dealt with similar issues at the U.S. Embassy in Iraq, likened the situation to a carnival game that promises a prize if you can guide a tiny, hand-controlled crane to the perfect spot: It almost never works and requires a steady stream of money.

"Everyone has known" about the minerals, she said, "but there's no way to get at it."

For one thing, Afghanistan lacks even the most basic resources for mining, such as railroads and electricity. It is expected to complete its first railroad this year.

And much of the minerals are in or around Taliban strongholds, which could encourage fighting to gain control of the deposits, said Sanok, a senior fellow at the Center for Strategic and International Studies in Washington.

Col. Dave Lapan, a Pentagon spokesman, said the $1 trillion figure did not surface until recently because Brinkley's task force had been preoccupied with Iraq. It wasn't until late last year that the task force got around to looking at a 2007 study by the U.S. Geological Survey. That is when the group determined the nearly $1 trillion estimated value, Lapan said.

The value of the mineral riches could rise even higher when taking into account the country's unknown reserve of lithium, a key ingredient in products from medicines to cell-phone batteries, potentially resting beneath dried-up lake beds scattered across the country.

Waheed Omar, a spokesman for President Hamid Karzai, said the $1 trillion figure was "very, very big news for the people of Afghanistan."