Much of the $19 billion in foreign aid that the United States has pumped into Afghanistan in the past decade may be fueling development on the ground in the short term, but is unlikely to produce change that will last once US troops depart, according to a new congressional report.

The Senate Foreign Relations Committee calls the report “the most comprehensive congressional investigation to date of US foreign assistance to Afghanistan.” It warns that while the US currently spends more on aid to Afghanistan than to any other country, that money is often not having a positive impact – and in many cases, may be contributing to corruption and to future economic woes for the poverty-stricken country.

The problem, the report points out, is that aid programs aimed to stabilize the country – and the great sums of money that accompany them – are at the heart of the US military’s counterinsurgency strategy in Afghanistan. “Our strategy assumes that short-term aid promotes stability in counterinsurgency operations and ‘wins hearts and minds,’ ” according to the study. "The evidence from Afghanistan supporting these assumptions," however, "is limited.”

Limited, it turns out, may be a bit of an understatement. The report goes on to warn that the large influx of money into the country may drive inflationary salaries (as much as 10 times the salary for an average Afghan worker) and pervasive corruption in the short term. In the long term, it may contribute to an economic collapse for Afghanistan if the country cannot afford to continue the programs that the US and other countries have started after international troops leave.

“We must challenge the assumption that our stabilization programs in their current form necessarily contribute to stability,” Sen. John Kerry (D) of Massachusetts, the chairman of the Senate Foreign Relations Committee, said in a statement Tuesday.

According to the World Bank, 97 percent of Afghanistan’s gross domestic product comes from foreign aid, including spending by the US military and international donors.

The report raises questions about the effectiveness of US aid to Afghanistan – for which President Obama has requested $3.2 billion in fiscal year 2012. At a time when the United States is facing its own economic crisis, some senators question whether such huge outlays are wise.

“Our geo-strategic interests are threatened not just by terrorism, but by debt, economic competition, energy and food prices, the proliferation of weapons of mass destruction, and numerous other forces,” Sen. Richard Lugar of Indiana, the committee’s top Republican, said Tuesday. “Solving these problems will be much more difficult if we devote too many resources to one country that historically has frustrated nation-building experiments.”

Senator Kerry, for his part, stressed that the report is “meant to be constructive.” The study also emphasized that the committee supports President Obama’s request for foreign aid to Afghanistan.

But that aid must be accompanied by some prudent future measures, according to the report. It suggests, for starters, stopping inflated salary payments to Afghan workers – what it called the “single most important step” to keep the inflated economy of the country from collapsing after US troop depart and foreign cash flow into the country inevitably ebbs.

The key, the report says, is to make current development funds fiscally sustainable for the Afghan government, since foreign donors currently cover “most of the costs of running the Afghan government.”

Future aid should focus heavily on building Afghan institutions such as roads and schools that the country must deliver – and can deliver, given its limited budget.

The report makes some recommendations that are likely to be less popular within the US military. In particular, it suggests that “in light of funding constraints, the State Department may want to consider a smaller footprint – a ‘civilian ebb.’ ”

Senior US military officers privately express concern that the “civilian surge” that was meant to accompany the influx of US troops into the country has largely failed to materialize and is confined largely to Kabul.

“The troop surge just has not been accompanied by the promised corresponding development and civilian surges,” says Norine MacDonald, president of the International Council on Security and Development, who is based in Lashkar Gah in the southern Afghan province of Helmand. “The gains that have been made on the battlefield are being undermined and put at risk by a lack of similar efforts in the fields of aid, development, governance, and counternarcotics.”

In a confirmation hearing Tuesday to be ambassador to Afghanistan, Ryan Crocker told the Senate Foreign Relations Committee that addressing corruption, which undermines the credibility of the Afghan state, and encouraging sustainable economic development, including employment, is crucial. “Failure in some of these areas can mean failure of the state and the creation of an environment in which our strategic enemies can regroup.”

Current US aid to Afghanistan is helping in some key areas like health and education, according to the report. “Undoubtedly, we will make some progress when we are spending more than $100 billion per year in that country,” Senator Lugar said Tuesday. “The more important question is whether we have an efficient strategy for protecting our vital interests that does not involve massive open-ended expenditures.”

And also, Kerry and others note, whether Afghanistan can sustain these critical improvements long after US troops have come home.