Last week, President Recep Tayyip Erdoğan reviewed the recent visit to Kobani by Brett McGurk, the U.S. special presidential envoy for the Global Coalition to Counter ISIS (DAESH).

Reacting to the visit to the town controlled by the Syria-based Democratic Union Party (PYD), which is an affiliate of Turkey's outlawed PKK, Erdoğan said: "How can we trust you [America]? Do you cooperate with us or the terrorists in Kobani?"

At a press conference on Feb. 8, U.S. State Department spokesman John Kirby responded to a question regarding Erdoğan's criticisms: "We don't, as you know, recognize the PYD as a terrorist organization. We recognize that the Turks do." Remarking that they would continue their talks with Turkey on the issue, he added: "Turkey is an ally, a friend and a partner."

Ankara responded harshly to Kirby's statement and summoned the U.S. ambassador to Ankara, John Bass, to the Foreign Ministry.

But why is Ankara so sensitive to the PYD issue? This question has only one answer, because the PYD and its armed People's Protection Units (YPG) are Syrian affiliates of the PKK, an illegal organization active in Turkey and recognized as a terrorist group by the U.S., EU and many other countries.

Kirby's remarks on why the U.S. does not recognize the PYD as a terrorist group are highly suspect. He says they favor the PYD since they have been in a struggle for sovereignty with DAESH in Kobani.

But, apparently, Kirby overlooks that YPG units fighting against DAESH in Kobani consist of PKK militants sent from the PKK headquarters in Northern Iraq's Qandil Mountains. In other words, the U.S. regards the PKK, which it recognizes as a terrorist organization within Turkey's borders, as an ally in Syria.

The PYD is also the periodic ally of the Damascus regime, which has violated the red lines of the U.S.

Speaking to Al-Jazeera, Mohammed al-Shamali, a former officer in the Syrian police department and one of the representatives of the moderate opposition in Syria, said that the U.S.'s disproportionate support for the PYD would cause some major problems:

"The YPG cooperates with [Syrian President Bashar] Assad and Russia while receiving a great deal of support from the U.S. at the same time. They benefit from both Russian and American air support while fighting against DAESH. Russian jets aid them while fighting opponents. The opposition under the umbrella of the Free Syrian Army, on the other hand, is obliged to fight against both DAESH and Assad's forces without having facilities equal to the YPG units."

Shamali also shared some striking scenes he bore witness to in the field that indicate the YPG operates against the U.S.

"Seizing the Manneh airport is crucial for Assad's forces at this phase since it is located in the northwest of Aleppo and in the south of Azaz. If it is seized by Assad's forces, the highway between Aleppo and Öncüpınar will be completely disconnected. We see that Assad's forces, the YPG and their ally the Jaysh al-Thuwar [Army of Revolutionaries] are in cooperation to seize it. Taking advantage of the advance of Assad's units, the YPG attacked and seized some villages where they have a cease-fire with Free Syrian Army, such as Meranaz and Der Jamal, which reveals this cooperation."

The PYD has been reinforced in the regions controlled by Assad and been organizing terrorist assaults on Turkey, which is its neighbor on the Syrian border. Moreover, the weapons the U.S. airdropped to the PYD as part of the fight for Kobani are now used in the PKK's violent assaults in Turkey.

The U.S. might think that periodic or temporary alliances with some terrorist organizations such as the PYD, which has been its ally in the Middle East for nearly 50 years, will not do any harm. However, as can be seen, the policy has both lead to critical damage in relations between the two countries and a strengthening of the U.S.'s regional rivals and enemies, in the short term.

To adapt a Turkish saying: The U.S. is likely to lose the bulgur in its pocket while attempting to get rice. That is to say the U.S. is likely to lose what it has while striving to have more.

The situation is reminiscent of U.S. policy toward the Taliban and al-Qaida, which were once supported by the U.S. as they were fighting against the Soviet Union, but then later struck their erstwhile supporter.