Tensions between the United States, its European allies and NATO member Turkey are at their highest point in recent history, prompting concerns about Turkey's continued position as a stalwart member of the alliance and partner of the West in maintaining regional security.

In the aftermath of last month's failed coup, Turkey's widespread crackdown on the military, media, judiciary and educators have raised eyebrows if not drawn outright criticism from the West and human rights groups. Meanwhile, Turkish leaders have complained that its NATO allies, in particular the United States, have not forcefully enough condemned the coup attempt, which they say was a direct assault on democracy supported by a cleric who lives in exile in the United States.

In a nod to Turkey's critical role, Gen. Joseph Dunford visited Turkey on Monday to reiterate U.S. condemnation of the coup and stress the high regard with which Washington views Ankara's partnership in the fight against the Islamic State group and its value as a NATO ally.

Here are some questions and answers about why many believe good relations with Turkey are critical, especially after the coup attempt:

Q: Why has the Obama administration trod lightly in expressing concern about the crackdown following the coup attempt?

A: The U.S. had high hopes for Turkish President Recep Tayyip Erdogan as an example of a democratic Muslim leader, and the Obama administration has vested interests in keeping him on its side, or at least in not alienating a powerful Muslim leader who is also an ally. In the aftermath of the failed coup, Erdogan lashed out at the United States, accusing it of insufficiently condemning the attempt to topple his government. President Barack Obama's administration has condemned the coup, but Erdogan has remained suspicious. When a senior American general expressed concern last week that the crackdown may affect the fight against Islamic State militants because some Turkish military officials have been jailed, Erdogan angrily told Gen. Joseph Votel to "know your place." Erdogan also accuses the United States of harboring the man he says was behind the coup attempt. That man, cleric Fethullah Gulen, has lived in self-exile in Pennsylvania since falling out with Erdogan. Turkey has demanded his extradition, but U.S. officials have demurred on whether a dossier submitted to the Justice Department represents a formal extradition request. U.S. officials have also said privately they have not yet seen evidence that Gulen was directly involved but have allowed that some of his followers may have been. Q: Why is Turkey so important?

A: Geography and demography for one. Strategically located north of the Middle East with borders on Syria, Iraq and Iran, Turkey serves as a bridge between Europe and Asia and more broadly straddles the divide between East and West. Its population of nearly 80 million is more than 99 percent Muslim, making it the only Muslim-majority member of NATO. Historically secular in governance and military matters, Turkey also served as a wedge between the former Soviet Union and the Middle East during the Cold War. Although Erdogan, the leader of an Islamist political party, has moved to boost religious influence in many spheres of society, the Obama administration and others see the nation as an important force, both symbolically and physically, in the fight against the Islamic State group in Syria and Iraq.

Q: What is Turkey's role in NATO?

A: Turkey joined NATO in 1952 along with rival Greece in the alliance's first expansion since it was founded three years earlier. It has the second largest standing army in the alliance after the United States, and has actively participated in the NATO mission in Afghanistan, which began after the alliance for the first time in its history invoked its Article 5 mutual defense clause after 9/11. Although it did not allow U.S. troops to access Iraq during the 2003 war, Turkey did provide support to the U.S. during the Gulf War. Turkey hosts Incirlik Air Base, a major hub for the air forces of Turkey and United States that has played a significant role in air strikes against Islamic State extremists. Full use of the base is vital and when power to it was cut after the failed coup, both U.S. diplomats and military officials made repeated appeals to the Turks to restore the electricity. Over the weekend, a Turkish police exercise outside the base briefly raised alarm before it was determined to have been a drill.

Q: What is Turkey's role in the region?

A: Since its days at the heart of the Ottoman Empire, Turkey has been a major player in the balance of power in the region. After WWII, Turkey, which borders the former Soviet Republics of Armenia, Azerbaijan and Georgia as well as Warsaw Pact member Bulgaria, served as a literal Cold War buffer. Since then, its differences with Greece over the Mediterranean island of Cyprus, a high-profile spat with Israel over the treatment of Palestinians and most recently its support for the ouster of Syrian President Bashar Assad have put Turkey in a position of influence. The United States and its allies are keen for Turkey to use that influence as a stabilizing force and to serve as a role model for Muslim democracies. Because of its location, Turkey also hosts hundreds of thousands of Syrian refugees and has been a key conduit for migrants fleeing to Europe. A recent agreement with the European Union that would see the return of refugees to Turkey may now be in jeopardy as EU officials have been slow to implement a visa-free travel regime for Turkish citizens.