There may be a finite number of countries in what is defined nebulously as the Middle East, but they do not always see eye-to-eye. That is due to the power struggle between and among various countries and religious sects within them. Iran and Saudi Arabia again play roles in their “war for influence.” Each has its allies and enemies, both within the region and globally. Consider Iran and Syria.

Iran and Syria are often cited as supporters of global terrorism. As a result, Syria has suffered from poor relations with many non–Middle Eastern countries over the years. But its relations with more moderate regional countries have not always been cordial due partly to the repressive tactics of Syrian President al-Assad and his father, Hafez al-Assad, who ran the country with an iron fist before him.

The sometimes brutal tactics used by the Assads in Syria and by deposed President Saddam Hussein in Iraq are related to religious factors. The Assads belong to the Allawites, who resorted to repression to maintain their grip on most of the key government and military positions in Syria. Similarly, Hussein repressed the majority Shi'ites (and Kurds) in Iraq to ensure that Sunnis maintained their power.

The same types of struggles exist between countries such as Iraq and Turkey, which have long been at odds over the Kurdish question. Even though Turkey provided some support for the Kurds in the northern part of Iraq, it also had concerns about its own security, especially as U.S. troops pulled out of Iraq in 2011.

The Turks were concerned with an incursion of Iraqi Kurds belonging to the PKK crossing their border and instigating violence. The Turks wanted strong border protection between the two countries to prevent PKK infiltration. They also wanted to limit Iran's influence in Iraq as the Turks and Iraqis forged stronger business bonds. The two countries engaged in $10 billion worth of bilateral trade in 2011, but very little of it took place in the northern part of Iraq, where it rose only 30 percent between 2006 and 2010. Such trade between Middle Eastern countries is essential as Iraq struggles to attract foreign investment to rebuild its economy and deteriorating infrastructure.

Relationships such as those between Turkey and Iraq, including their mutual goal of limiting Iranian influence, and the interplay among Syria, Saudi Arabia, and Iran are commonplace in the Middle East—which is by no means a “one size fits all” region.