It is time to "talk turkey" about Turkey's role in NATO.

Despite U.S. President Barack Obama's "good friendship" with Turkish Prime Minister Recep Tayyip Erdogan, the country's leadership continues down a worrisome path that should give NATO members pause to question Ankara's allegiance. A most disturbing disclosure by Turkey, only recently revealed, has undermined the United States' ability to accurately evaluate Iran's nuclear arms program.

Formed in 1949, NATO has grown from 12 to 28 countries. In 1952, Turkey -- motivated by Soviet leader Josef Stalin's stated desire to control the Turkish Straits -- joined.

NATO members enjoy a collective "all for one and one for all" defense. Ankara valued this as it brought it under the United States' protective umbrella.

Turkey's role in NATO took on added significance once Islamic extremism became more of a threat. Strategically located between Europe and the Muslim world, it became a role model for effective democracy in the Arab world.

The founder of the Republic of Turkey and its first president, Mustafa Kemal Ataturk, recognized prosperity turned on the country taking a secular road. Although opposed by Islamists, he strongly focused on Western education, building thousands of schools.

Like the phoenix arising from the ashes of an economically stagnant Ottoman Empire, Turkey enjoyed immense prosperity as Ataturk built the foundation for a modern nation.

Ataturk realized Turkey's road to modernization could encounter Islamist resistance. He, therefore, sought to minimize its influence. Fearing sovereignty "would return under the guise of a caliph," he saw it necessary to abolish the concept of the "caliphate" -- a core political foundation of Sunni Islam, which imposed Shariah law.

Speaking before Turkey's Parliament, Ataturk said, "The religion of Islam will be elevated if it will cease to be a political instrument, as had been the case in the past."

On March 3, 1924, the caliphate concept was officially abolished; the following month so were Shariah courts.

Ataturk astutely recognized, too, the need to empower the military to safeguard democracy against Islamist influence. The 1921 constitution noted the military's duty "to protect ... the Turkish Republic as stipulated by the constitution." The duty was repeated in each subsequent constitution -- until 2001.

Prior to 2001, the military exercised its constitutional right on several occasions, interfering in political matters when it perceived a threat to the secular state, later returning control to civilian authority.

But Islamist influence managed to seep back into Turkish politics with the rise of the Justice and Development Party, known by its Turkish initials AKP, formed by Erdogan in July 2001. Its rise didn't signal Islamist popular support as much as frustration over corruption by the ruling party. Three months later a significant constitutional change stripped the military of its constitutional guardianship duty.

Ever since AKP's rise, Erdogan has sought to steer the government from secularism and toward Islamism. He has endeavored to replace the Western education introduced by Ataturk with one preaching Islamist principles. When educators objected, they were detained by police.

Becoming concerned about increasing Islamist influence, the military posted an Internet statement noting its dissatisfaction. Erdogan quickly reminded the military it no longer had constitutional authority to act.

After an effort failed to declare AKP illegal due to its Islamist platform, Erdogan went after critics, charging several senior military, journalists and academics with trumped up coup allegations. The military protectors of Turkish democracy were silenced.

Somali-born human rights activist Ayaan Hirsi Ali, who has felt Shariah's brutal sting, wrote in a 2007: "Secular and liberal Turks have had a rude awakening from years of deep slumber. Kemal Ataturk's heritage is about to be destroyed -- not by an invading power but from within, by fellow Turks who yearn for an Islamic state."

NATO, too, is in a deep slumber.

Slowly being led back to Islamism, Turkey poses a threat to the alliance on two fronts -- the sharing of intelligence and of nuclear weapons.

It was recently learned Ankara revealed to Tehran the identities of 10 alleged Israeli spies working in Iran. The loss of the agents -- critical to assessing Iran's progress on its nuclear arms program -- significantly damaged U.S. intelligence efforts as well.

What was Erdogan's motivation for the 2012 disclosure? Revenge -- revenge for Israel's 2010 boarding of the Turkish-organized Gaza Flotilla that left nine Turkish citizens dead. As an Israel-Turkey intelligence partnership had secretly existed since 1958, the Israelis were shocked by Ankara's betrayal.

The betrayal did spark the U.S. Congress to quietly cancel delivery to Turkey of 10 unmanned aerial vehicles in June 2012.

Surprisingly, despite the sectarian rivalry between Sunni Turkey and Shiite Iran, the latter's intelligence chief maintains a friendly relationship with his Iranian counterpart.

Even more worrisome, however, is NATO's nuclear-sharing policy under which member states lacking nuclear weapons get them for storage and use as part of the alliance's strategic planning.

Turkey has 70-90 U.S. B61 nukes under the program. All are at Incirlik Air Base, most of which are kept in a constant readiness state for immediate loading onto U.S. bombers. The United States plans to give Turkey its newest nuclear weapon in 2019. While U.S.-installed safeguards exist on the weapons, in the world of high technology nothing can be an absolute guarantee.

Erdogan is clearly leading Turkey out of the democracy camp and back into an Islamist one. The journey is one about which both the Turkish people and NATO should be very, very concerned.

(A retired U.S. Marine, Lt. Col. James Zumwalt served in the Vietnam War, the U.S. invasion of Panama and the first Gulf War. He has written "Bare Feet, Iron Will -- Stories from the Other Side of Vietnam's Battlefields," "Living the Juche Lie: North Korea's Kim Dynasty" and "Doomsday: Iran -- The Clock is Ticking.")

(United Press International's "Outside View" commentaries are written by outside contributors who specialize in a variety of important issues. The views expressed do not necessarily reflect those of United Press International. In the interests of creating an open forum, original submissions are invited.)