The case of an Afghan man who could be prosecuted and even put to death for converting to Christianity has unleashed a blizzard of condemnation from the West this week and exposed a conflict in values between Afghanistan, a conservative Muslim country, and the foreign countries that have helped defend and rebuild it in the four years since the fall of the Taliban.

The case of Abdul Rahman, a longtime Christian convert who lived in Germany for years and was arrested last month in Kabul, has also highlighted the volatile debate within Afghanistan over the proper role of Islam in Afghan law and public policy as the country struggles to develop a democracy.

Diplomats from several countries said yesterday that Rahman, 41, now seems unlikely to be tried or executed. Prosecutors in Kabul said he might be mentally unfit to stand trial, a sign that the government may be seeking to avoid confronting its Western allies without giving ground on Islamic law, under which conversion to another religion is punishable by death.

But the case, the first of its kind since the radical Islamic Taliban movement was toppled in 2001 by a U.S.-led military invasion, continued to draw protests from the governments of Italy, Germany, Canada and other NATO nations, at a time when NATO forces are beginning to replace tens of thousands of U.S. troops as the principal defenders of Afghanistan against Taliban and al-Qaeda insurgents.

It also put pressure on President Bush, who visited Kabul last month to show support for Afghan President Hamid Karzai. A number of U.S. Christian and conservative groups demanded this week that Bush take action, and one organization accused him yesterday of propping up an Islamic fundamentalist regime in Kabul.

"This is an extremely sensitive issue here and an extremely serious issue back home," Abdullah, Afghanistan's foreign minister, said in an interview yesterday with Washington Post editors and reporters. "Every time we have a case, it is like an alarm. These contradictions will not go away with one or two cases."

Bush, on a visit to Wheeling, W.Va., said yesterday he was "deeply troubled" to learn of Rahman's possible prosecution. "That's not the universal application of the values that I talked about" while in Kabul, he said. He stopped short of calling for the case against Rahman to be dropped but said he would work with Karzai's government "to make sure that people are protected in their capacity to worship."

Bush's comments were tougher than those made previously by administration officials. On Tuesday, a State Department spokesman urged the Afghan government to "conduct any legal proceedings in a transparent and fair manner." R. Nicholas Burns, the undersecretary of state for political affairs, said that the Afghan constitution "affords freedom of religion to all Afghans" and that the U.S. government hoped for a "satisfactory result" of the case.

The initial low-key response apparently infuriated Christian conservative groups. Tony Perkins, president of the Family Research Council, complained in a letter to Bush and Secretary of State Condoleezza Rice: "How can we congratulate ourselves for liberating Afghanistan from the rule of jihadists only to be ruled by radical Islamists who kill Christians? . . . Americans will not give their blood and treasure to prop up new Islamic fundamentalist regimes."

In another open letter to Bush, the U.S. Commission on International Religious Freedom said it was "the obligation of our government" to take action in the case. The group warned that in Afghanistan, there is no legal guarantee of religious freedom and the judiciary is instructed to enforce Islamic principles. "The door is open for a harsh, unfair or even abusive interpretation of religious orthodoxy to be officially imposed," it said.

Bush, a Christian, often talks about God, faith and respect for all religions, especially in relation to the war on terrorism. The White House has often portrayed Karzai as an example of a Muslim leader and ally who is working to hunt down Islamic terrorists and build a democracy based on the rule of law and human rights.

But Afghanistan is also a deeply traditional and tribal society, where 99 percent of the 25 million inhabitants are Muslims and no Christians worship openly. It is a capital crime under Afghan Islamic law to convert to Christianity, and prosecutors and judges in Kabul initially said Rahman might be sentenced to death.