Turkey is embroiled in a war over the future of its separation of church and state. After pro-Islamist Prime Minister Recep Tayyip Erdogan nominated Foreign Minister Abdullah Gul to run for the presidency, massive pro-secularist protests broke out in Ankara and Istanbul.

On May 5, hundreds of thousands of pro-secularist Turks—afraid of what direction an Islamic-leaning leadership would take their country—took to the streets in protest. One million gathered in Istanbul the previous Sunday and roughly 300,000 gathered three weeks earlier.

Despite Mr. Gul’s statements that the next president of Turkey “must be loyal to secular principles” and that, if elected, he would “act accordingly,” his background in Islamic politics has many secularists worried.

However, Mustafa Ozyurek, deputy chair of the main opposition party, the Republican People’s Party, told the Associated Press that “there is no evidence that [Mr. Gul] is sincerely loyal at heart to the secular republic and principles of Atatürk.”

Although largely a Muslim country, Turkey is an exception in the Middle-East. While Islam is quickly spreading throughout the region, strong secular forces in Ankara, backed by the military and a large percentage of the population, bristle with the thought of Turkey becoming more Islamic than it is currently. Mr. Erdogan’s party, the Justice and Development Party (AKP), holds a majority in Turkey’s parliament. Some fear if Mr. Gul were elected President, the pro-Islamist AKP would then be in control of both the parliament and the presidency—and that many of their rights would be taken away.

With the current president’s seven-year term ending May 16, Mr. Erdogan also caused controversy when he called for early presidential elections. In response, the secularist military threatened a coup if early elections were allowed.

According to Der Spiegel, “The country’s military issued a statement that it was ‘the absolute defender of secularism’ and would prove it if need be.” With Turkey’s history of military coups, another one is not unlikely. The latest coup occurred in 1997 when a pro-Islamist government was overthrown.

Nonetheless, in a move that slightly eased tensions, the Turkish high court called off what would have been the first round of parliamentary elections. It declared that a vote would be unconstitutional because not enough parties were involved.

Mr. Erdogan, upset with the court’s decision, has now proposed changing the constitution to allow the people to vote on a president. When presidential elections are to occur has yet to be decided.