U.S. calls Afghanistan "greatest military challenge"

Soldiers with the U.S. Army's 6-4 Cavalry walk down a mountain path during a patrol near Combat Outpost Keating in eastern Afghanistan January 24, 2009.

WASHINGTON (Reuters) - U.S. Defense Secretary Robert Gates on Tuesday described Afghanistan as America's greatest military challenge and warned the war could be lost if the West failed to address the problem of civilian casualties.

Gates, appearing before the Senate Armed Services Committee, also said Iraq still held the potential for setbacks even as the U.S. force there winds down under a U.S.-Iraqi pact that calls for troops to leave by 2012.

"There is little doubt that our greatest military challenge right now is Afghanistan," he said. "President (Barack) Obama has made it clear that the Afghanistan theater should be our top overseas military priority."

In his first testimony as Obama's Pentagon chief, Gates said Afghanistan posed a long and difficult fight that could be expected to bring rising U.S. casualties and war costs.

He also told lawmakers that the main U.S. goal should be an Afghanistan free of Taliban rule and al Qaeda safe havens.

"If we set ourselves the objective of creating some sort of Central Asian Valhalla over there, we will lose because nobody in the world has that kind of time, patience or money."

He also defended U.S. missile strikes on militants in Pakistan, saying the Obama administration, like its predecessor, would hit al Qaeda where the network operates.

CIVILIAN DEATHS

Gates said the United States must ensure Afghans see the battle against the Taliban and other insurgents as their own struggle. Civilian deaths caused by U.S. and NATO operations had already done enormous harm to American interests, he said.

"My worry is that the Afghans come to see us as part of the problem rather than part of their solution, and then we are lost," Gates said.

Last weekend, Afghans protested a U.S.-led operation in which the U.S. military said 15 militants died. Local Afghans said at least 10 of the dead were innocent civilians.

"We need to get the balance right in this in terms of how we interact with the Afghan people or we will lose," he said.

The Obama administration is considering almost doubling the U.S. force in Afghanistan from 36,000 to more than 60,000 within 18 months to battle an increasingly intense insurgency.

Gates warned against further increases in U.S. troops that could make the United States appear as an occupier.

He said ultimate success in Afghanistan lies with a multibillion-dollar plan to boost the Afghan national army from 80,000 troops to 134,000.

"A strong Afghan National Army and a capable, reasonably honest Afghan National Police ... represents the exit ticket for all of us," he said.

THE IRAQ FACTOR

An extra Army brigade of some 3,500 troops is deploying to eastern Afghanistan this month and Gates said another three could deploy by mid-summer if Obama approves the plan.

The Pentagon's ability to ramp up forces in Afghanistan depends partly on how quickly it can withdraw them from Iraq, where 142,000 U.S. troops are deployed.

Obama and top military officials were set to discuss withdrawal options at a Pentagon meeting on Wednesday.

Violence in Iraq has fallen sharply over the past year, but "there is still the potential for setbacks," Gates said.

"As our military presence decreases over time, we should still expect to be involved in Iraq on some level for many years to come."

Gates, who appeared in the U.S. House of Representatives later in the day, said deployment strains on combat forces should ease even as the force in Afghanistan increases.

Troops should start to spend 15 months at home for every 12-month deployment by October, followed by two years at home for each one-year deployment a year later and 30 months at home by October 2011.

(Additional reporting by Andrew Gray and Andrea Shalal-Esa; Editing by Xavier Briand)