Joshua Roberts/Reuters
The apex was perhaps on Wednesday, when reports emerged that Erdogan had hosted a closed-door dinner for Washington's foreign policy establishment- including think tankers and former government officials - the night before.
During that meeting, he reportedly blasted Obama for using Syrian Kurdish fighters as a proxy force to fight the Islamic State terror group.
"He pretty much threw the administration under the bus," one attendee told Foreign Policy's John Hudson. "The biggest message I heard from Erdogan was: 'You need us. You can't win your war in Syria without us.'"
Erdogan ended up meeting with Obama on the sidelines of the nuclear summit, in a gathering the White House said "reaffirmed the support of the United States for Turkey's security and our mutual struggle against terrorism."
Joshua Roberts/Reuters
"While the Europeans embrace Turkey because of the refugee crisis, turning a blind eye to Erdogan's campaign against the Kurds in Syria and his own domestic opposition (free press included), he's getting hammered by Obama for not getting on board to fight ISIS first and foremost in Syria."
Erdogan officially joined the anti-ISIS coalition in July 2015, launching limited airstrikes against ISIS targets in Syria and allowing the US to use Turkey's Incirlik airbase for its air campaign against the jihadists.
But Obama apparently still feels Erdogan is devoting too many resources to his fight against the Kurdistan Workers' Party (PKK) in the southeast - and not enough to sealing off its southern border with Syria and stopping the back-and-forth flow of foreign fighters. The administration has also condemned Erdogan's suppression of free speech and policy of jailing journalists who criticize him.
Murad Sezer /Reuters
"Erdogan has a fiery temper and has plenty of friends in the beltway - they're a serious military equipment purchaser and more generally an important market for plenty of US companies," Bremmer said. "On top of that, they're a NATO ally that's had their territory regularly breached by the Russians, but they get none of the support that Poland and the Baltic states have been receiving."
Bremmer pointed to an incident in November, when Turkey shot down a Russian warplane that had purportedly violated its airspace and the White House told Erdogan to "cool it, in no uncertain terms."
"Now Russian sanctions are taking a big bite (some $10 [billion] a year) out of Turkey's economy," he said.
Dr. Aykan Erdemir, a senior fellow at the Washington, DC-based think tank Foundation for
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Erdemir characterized Erdogan's visit as a "publicity stunt," noting that the leader may be able to use the trip to boost his image at home. But he added that Erdogan had expected that he would not be granted "a royal welcome in Washington," which may explain why he has not made much of an effort to soften his image here in the US.
During a televised appearance at the Brookings Institution on Thursday, Erdogan's security detail roughed up reporters waiting to get inside. Brookings reportedly threatened to cancel Erdogan's invitation in response to his security guards' behavior, which evidently began before Erdogan even arrived at the think tank.
While there, moreover, Erdogan responded to a question about his country's practice of jailing journalists by saying that "only seven of them [in jail] are actually journalists ... and at least four have ties to terrorists."
Joshua Roberts/Reuters
"Erdogan is aware that the Turkish economy is on the verge of a downward spiral, and he is desperate about attracting foreign direct investment," Erdemir said. "He is trying to reassure potential investors worried about the lack of rule of law in Turkey that even under his authoritarian rule business could be profitable."
Bremmer largely agreed.
"Erdogan is having troubles at home ... and can't muster the support to change the constitution so he can make himself into a Turkish Putin," he told Business Insider. "That's extraordinarily frustrating for him, and has made him more insecure, unpredictable, and more willing to lash out at his uncertain ally, the United States."