My visit to Istanbul this week comes in the midst of the greatest challenge to the Turkish secular republic since its creation in 1923.

Founded by Mustafa Kemal Ataturk out of the wreckage of the Ottoman Empire, the republic came into existence at the high water mark of Western confidence, when it appeared that European ways would become the global template. As president, Ataturk imposed a dizzying array of changes, including European laws, the Latin alphabet, the Gregorian calendar, personal last names, hats instead of fezzes, monogamy, Sunday as the day of rest, a ban on dervishes, the legal right to drink alcohol, and Turkish as a liturgical language.

Many of the reforms took root; going back to the Arabic script or discarding last names is now inconceivable. That said, the country has generally reverted to Islamic ways. Increased religious instruction in the schools and more state-funded mosques are complemented by more women taking on headscarves.

Several factors account for this development: a predictable reaction against Ataturk’s excesses; Turkey’s greater democratization, which gave the masses a chance to express themselves; the higher demographic rate of Anatolians, who were generally cooler to Ataturk’s changes, and an Islamist surge that began in the mid-1970s.

Islamist efforts have translated into their gaining substantial representation in the Grand National Assembly, beginning as a single seat in the 1960s, then — aided by Turkish electoral peculiarities — reaching nearly a two-thirds majority in today’s parliament. Islamic parties have twice controlled the prime ministry, in 1996–97 and since 2002. The first time, Prime Minister Erbakan’s headstrong personality and overt Islamist program prompted the Turkish military, guardians of Ataturk’s traditions, to oust him from power a year later.

After Mr. Erbakan’s collapse, a former lieutenant, Recep Tayyip Erdogan, founded the Justice and Development Party (or AKP), now the governing party. Learning from the 1996–97 fiasco, Mr. Erdogan and his team took a much more cautious approach to Islamicization. They also were competent at governing and have handled the economy, the European Union, Cyprus, and other matters reasonably well.

But last month, Mr. Erdogan reached too far. He chose a close associate, Abdullah Gül, to run for the republic’s presidency. In a fast-paced sequence of events, Mr. Gül failed to get the necessary votes, the Constitutional Court voided the election, millions of secularists took to the streets, the military hinted at a coup, and Mr. Erdogan dissolved the parliament. Both it and a new president will soon be voted on.

Questions abound: Can the AKP again win a majority of seats? Failing that, can it form a ruling coalition? Can it succeed in installing one of its own as president?

More fundamentally, what are the AKP leadership’s intentions? Does it, having witnessed Mr. Erbakan’s fate, retain a secret Islamist program and has it simply disguised its goals? Or has it actually given up on those goals and accepted secularism?

The question of AKP’s intent can only be answered speculatively. A trip to Turkey in mid-2005 showed persuasive evidence both for and against a hidden Islamist agenda; on this visit, two years later, I find that what I called a “sophisticated intellectual puzzle” regarding AKP’s plans remains just that. There are just more data to process and interpret.

Each Turk must judge the AKP for himself, as must key foreign governments. Current polling shows that Turkish voters are still quite undecided; foreign leaders, however, have opted in Mr. Erdogan’s favor: The Council of Europe has condemned any threat of military intervention, and Secretary of State Rice has gone even further, praising the AKP for “pulling Turkey west toward Europe” and specifically endorsing its efforts to make Turkey’s laws conform to those of Europe in the areas of individual and religious freedom.

But her statement ignores AKP efforts to apply Islamic law by criminalizing adultery and creating alcohol-free zones, not to speak of its privileging Islamic courts over secular courts, its reliance on dirty money, its bias against religious minorities, and its persecution of political opponents.

Further, European Union membership offers the AKP a huge side benefit: By reducing the political role of Turkey’s arch-secular military leadership, paradoxically, it eases the way to apply Islamic laws. Could the AKP’s caution about Islamicizing outlast a neutering of the officer corps?

Ms. Rice also ignores the AKP-induced tensions in relations between America and Turkey. But her superficial analysis has had one inadvertent benefit: Given Turkey ‘s current fervid anti-Americanism, American support for the AKP just might cause the party to lose votes.

Such cynical humor aside, Washington should stop bolstering the AKP and instead side with its natural allies in Turkey, the secularists.

Mr. Pipes (www.danielpipes.org) is the director of the Middle East Forum.