The Pentagon wants $33 billion in additional funding to pay for the war in Afghanistan this year and train the Afghan military, but members of Congress want to make sure they’re not writing a blank check.

Defense Secretary Robert Gates and Secretary of State Hillary Rodham Clinton appeared before Senate appropriators to defend the war supplemental, which is on top of the $708 billion baseline budget submitted to Congress in February.

Most of the war supplemental – a separate account used to pay for war costs – will pay for Afghanistan operations. Of that, $2.6 billion is to train the Afghan national security force, seen as a long-term endeavor that Congress worries could become a burden over time.

When can US forces leave?

“The question is, how long is that going to have to continue to the point where we can kind of say we’ve done our thing,” asked Sen. George Voinovich (R) of Ohio. “Five years, ten years, 15 years?”

That question is atop many lawmakers minds as they consider what the Obama administration has said from the start will take years to accomplish.

The Iraq security forces, now nearly 665,000 strong, took at least six years to build. But Iraq had more resources, and American trainers were already working within a culture in which a formal military existed under Sadaam Hussein. Afghanistan’s modern history has never had a formal military structure, and there are even fewer resources in Afghanistan to support one.

Despite contributions from NATO countries, that still leaves the US holding much of the bag when it comes to training the Afghan indigenous force.

While President Obama has pledged to begin removing American troops from Afghanistan in 2011, the training mission will likely continue long after that.

“We are in this intense phase that will be several years,” Ms. Clinton said in answer to Mr. Voinovich’s question. “Obviously, I don’t know that either of us could put a timeline on it. What we’re trying to do simultaneously is clear territory from the Taliban, be able to work more closely with the Afghan army, and at the same time create more capacity.”

Although NATO allies contribute to the training effort – Germany, for example, the third largest contributor of forces to Afghanistan, is almost uniquely charged with training operations in the north – the US will shoulder much of the burden for the long-term.

US commanders concerned about Afghan forces

“I know many of you have concerns about the Afghan security forces,” Mr. Gates said in his opening statement. “I share those concerns, as do our military commanders.”

Gates noted that the Afghan army has made “real progress” over the last year, and that many Afghan soldiers are making enormous sacrifices for their country. But Gates emphasized that the US can get out of Afghanistan faster if the training piece of the mission is done right, and that will likely take time. And while much praise goes to the Afghan army, the police force – seen as widely corrupt – will be a much harder fix.

“As you consider this request, I would emphasize that successfully accomplishing the training mission represents both our exit strategy and the key for long-term stability in Afghanistan,” Gates said.

But as a reminder of the cost of training indigenous militaries, the $33 billion funding request includes $1 billion still needed to strengthen Iraqi security forces, a force many consider to be all but fully trained as the US prepares to remove all its combat forces by August.

Gates said the money will help to “ensure that the Iraqis are fully prepared to assume internal security responsibilities.”