A sigh of relief went up in Washington this week that could be heard around the world.

Abdul Rahman, the Christian convert in Afghanistan who faced execution for renouncing Islam, has been released and spirited off to Italy (to avoid being killed by mobs).

A State Department spokesman pronounced the United States "pleased" by this development, diplomat-speak for "thank God this nightmare is over." After the deaths of hundreds of Americans and the expense of billions of dollars, the specter of Rahman's execution by the new democracy we helped create to replace the Taliban was an embarrassment the U.S. government could ill afford.

But Rahman's release will not solve the larger problem — this incident is just the tip of a very ugly iceberg. According to Compass Direct, a Christian news agency, two other Christian converts have been arrested in recent days and several other Afghan Christians report police raids on their homes and places of work over the past month. This is nothing new. The small numbers of Christians who haven't fled Afghanistan live in constant fear of harassment or worse.

It's not just Christians. Freedom House, a nongovernmental human rights organization, reports that Afghan journalists and others who dared to criticize Islamic law have been charged with heresy or blasphemy.

Rahman's close call brings to the surface the fundamental flaw that threatens to destroy Afghanistan's fledgling democracy: On one hand, the new constitution guarantees freedom of religion and expression, committing the nation to upholding the Universal Declaration of Human Rights. On the other hand, the constitution states that "no law shall contravene the tenets and provisions of the holy religion of Islam." The arrest of Abdul Rahman for apostasy is a stark reminder that Afghans must choose between religious freedom and theocracy. They can't have it both ways.

I'm not suggesting that Islamic law or sharia is inherently incompatible with religious freedom. Moderate Muslims frequently quote a Quranic verse, "Let there be no compulsion in religion." But sharia, like biblical law, is open to a wide range of interpretations. In the hands of fundamentalists, like Afghan Supreme Court Chief Justice Fazl Hadi Shinwari, sharia heresy and blasphemy laws are used to deny religious freedom.

Americans, especially evangelical Christians, were first in line to condemn the theocratic oppression on display in the Rahman case. After all, most of us take as "self-evident" that religious freedom is the birthright of every person. We rely on the First Amendment to keep government from imposing religious law on the nation. Fortunately, the "holy commonwealth" of Massachusetts Bay Colony is a distant memory.

Or is it? Are Americans quick to see the evils of theocracy abroad, but slow to recognize creeping theocracy at home?

That's my question after reading American Theocracy, a new book by former Republican strategist Kevin Phillips. In foreign affairs, environmental and science policies, and economic decisions, Phillips argues, the growing influence of what he calls "radical religion" on government threatens the future of American democracy.

At times Phillips indulges in hyperbole and overuses the "theocrat" label. The dangers he cites are nonetheless real. When leading politicians and some televangelists rail against the principle of church-state separation, claiming that it isn't in the Constitution, they undermine public support for a secular nation that guarantees religious freedom for everyone.

The irony is inescapable. Some of the same American evangelicals who demand separation of mosque and state in Afghanistan and Iraq have repeatedly condemned the "myth" of "separation of church and state" at home.

To be fair, there are secularists who fuel this hostility to "separation" by misusing the term to push for keeping religion out of the public square. That's not what the framers intended. Under the First Amendment, Americans have the right to bring their religion into politics or public life — but government is barred from imposing religion on the people.

The words "separation of church and state" may not be in the Constitution, but the principle is not only in the First Amendment (that's what "no establishment" means), it is also the bedrock of religious freedom in America. That's why in the United States, unlike Afghanistan, religious law cannot trump our constitutional commitment to universal human rights.

Kabul is a long way from Washington, D.C. But the dangers of radical religion shaping government policy may be close at hand. As James Madison warned during the battle to separate church from state in Virginia, "It is proper to take alarm at the first experiment on our liberties." Religious freedom and theocracy — whether Muslim or Christian — can never coexist.