A military aircraft on the runway at Incirlik Air Base, in the outskirts of the city of Adana in southeastern Turkey in July 2015. (AFP/Getty Images)

As members of the military attempted to overthrow the Turkish government this weekend, you can bet many North American and European leaders watched the outcome with bated breath. That's not just because Turkey is a regional powerhouse; the country is also a key part of NATO, the most important military alliances in the Western world.

Instability in the country could cause blowback across that alliance. Even now that President Recep Tayyip Erdogan and his supporters seem to be firmly back in control, those fears have not been totally allayed. On Monday, Secretary of State John F. Kerry said NATO will be scrutinizing whether Turkey keeps meeting the alliance's requirements for democracy and rule of law in the days after the failed coup attempt.

Why the worry? Turkey is certainly not the first NATO member to be rocked by a coup, whether the coup succeeded or not. Since the alliance was founded in 1949, there have been coups in France, Greece, Portugal (all successful) and Italy (unsuccessful). In Turkey alone, there were three coups between 1960 and 1980, as well as a "postmodern" coup in 1997 which saw the military collapse a government by simply threatening to intervene.

However, Turkey occupies an especially strategic place in the alliance. One factor is its sheer size. With a population of 79 million, the country is the third largest in NATO. It has 426,000 military personnel last year, the second largest of any NATO member state.


 

Turkey's geography is also vital. During the Cold War, Turkey butted right up against Soviet states and Moscow's traditional sphere of influence. In the conflicts of the 21st century, it's location has become useful once again. The country sits atop the Middle East. It is the only Muslim-majority member of the alliance and has formed an important part of the U.S.-led international military coalition against Islamic State militants in Syria and Iraq.


The remarkable cooperation between Turkey and the United States, its NATO ally, can be seen best at Incirlik Air Base in the southeast of Turkey. The base was built at U.S. initiative: U.S. Army Corps of Engineers began construction in 1951. In 1954, the Turkish General Staff and the U.S. Air Force agreed to use it together. During the Cold War, the base was used to fly U-2 spy planes, among many other things. Since last October, U.S. troops with a direct role in the military campaign against the Islamic State use the base. U.S. troops also use an air base in Izmir and the Aksaz Naval Base.

Not only is Incirlik a major NATO installation, the U.S. forces that are stationed there also control a significant number of nuclear weapons — perhaps more than any other NATO base, according to Eric Scholler of the New Yorker. The base's proximity to Syria, just 70 miles or so, have led to attempts to better protect this arsenal a few months ago with upgrades to the security fence.

The coup complicates this relationship in a number of ways. As a result of the coup attempt, there has been a huge purge of not only the military, but also the police force and the civil service. The removal of these people not only calls into question Turkey's suitability as a NATO partner, but also its continuing capabilities: The Guardian reports that one top official in the fight against the Islamic State is said to have been found dead after meeting with the coup plotters. And as Kerry noted on Monday, NATO states are expected to meet certain requirements regarding rule of law; reprisal attacks may not meet those standards.

To make matters worse, at least some of the plotters appear to have been based at Incirlik Air Base. This not only calls into question the safety of the weapons housed there, but it also raises uncomfortable questions about how and when U.S. soldiers may have discovered the coup plot.

A failed coup only adds to an already heady mix of worries about Turkey's role in NATO. American and European leaders have frequently voiced concern at Erdogan's apparently autocratic tendencies. Turkey appears to have long turned a blind eye to Islamic extremists, only gearing up in the fight against the Islamic State when it may have been too late. In recent years, a conflict with the country's Kurdish minority has reignited — complicating many NATO members' relationships with Kurdish allies in Syria and Iraq.

And yet somehow, things now seem even worse.

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