WELLESLEY - In a Sunday debate, U.S. Rep. Barney Frank and challengers Susan Allen and Earl Sholley offered significantly different views on the causes of Afghanistan's recent deterioration and how to reverse it.

Allen, a Democrat who is running as an independent, blamed the CIA for Afghanistan's downward spiral and presented a theory that links Afghanistan's drug production with the now-accepted conclusion that the 9/11 attacks originated in Afghanistan.

"Afghanistan used to be a healthy country," she said. "It has been alleged that the CIA highly encouraged the people of this country to grow drugs. And these drugs were used obviously not for food but for exportation. This is the allegation. And then when the farmers, in conjunction with the government, tried to pull back and reduce the percentage of drugs grown for exportation this country, it was decided that Afghanistan attacked the United States on 9/11."

Allen said that the CIA and the United State should stay out of Afghanistan.

"If our CIA, in conjunction with other intelligence around the world, would only leave the people of Afghanistan alone and allow them to grow their own crops, and have sustainable economy, perhaps their government and these people and these farmers would do a lot better," she said. "It's time for us to stop policing the world...We're destroying democracy and we don't' belong there."

Frank, a Newton Democrat, took issue with Allen's theory.

"I have to come to the defense of the CIA," he said. "I am disturbed by the method of argument that says, ‘It was alleged that the CIA introduced drugs into Afghanistan.' I think that is an outrageous kind of charge to make based simply on an allegation."

Frank also said that it is clear that when the United States invaded Afghanistan, the Taliban, which he called "one of the most vicious, immoral, anti-human rights organizations around," was running the country.

"And, in fact," he went on, "that had been the place from which we were attacked. Osama Bin Laden was in Afghanistan when he attacked us."

Frank said that believes the United States should have pursued a more aggressive policy in Afghanistan from the beginning instead of devoting energy and resources to Iraq. The decision to go into Iraq, he said, is the "greatest single mistake in American foreign policy history" and caused Afghanistan to become a "side show" that lead to "an increase in strength of the Taliban."

"We never should have gone into Iraq," he said. "We should be withdrawing from Iraq as rapidly as possible so we can more sensibly pursue a pro-democracy, anti-terrorist policy in Afghanistan."

Sholley, the Republican in the race, said the United States had the opportunity to, but fell short of, developing close ties to Afghanistan after helping it expel the Russians in the 1980s.

"We made a mistake, we should have cultivated a closer relationship with the Afghani people," he said. "We didn't do that. That was a failure of our diplomacy.

Sholley also said that the United States needs to turn to allies for help in Afghanistan.

"But, just like Iraq," he said, "I think we are in a situation right now where our allies need to step up and shoulder more of the burden. I think we should stabilize it as much as we can."

But Sholley also agreed with Allen that the United States "cannot continue to be policemen for the world."