President Recep Tayyip Erdoğan will arrive in Washington, D.C. today to meet with President Donald Trump at the Oval Office. This will be the first face-to-face meeting between the two leaders and without doubt one of the most significant summits between the leaders of two countries in the recent history. The meeting is taking place following the decision of the Trump administration to directly arm the outlawed PKK's Syrian wing, the People's Protection Units (YPG). This was the plan of the Obama administration and it has derailed Turkish-U.S. relations for the last few years. Since the beginning of the conflict in Syria, the Obama administration made several decisions about the civil war in Syria and these decisions were strongly criticized each and every time by the regional experts. These decisions of the Obama administration also resulted in serious tensions in the relations of the U.S. with its allies in the region. Resigning to the Bashar Assad regime killing thousands of civilians in Syria was a colossal mistake, as seen by the regime's use of chemical weapons in August, 2013. Tolerating the expansion of proxy groups in Syria in order to reach a nuclear deal with Iran was another mistake that took place during this period. The aversion of the Obama administration to take punitive action against the Assad regime and deter its further use of chemical weapons was another major policy error that led to the increasing use of conventional force by the regime to further intensify its crackdown. This decision also leads to the further empowerment of radical groups by spreading the indecisiveness and inaction of the international actors. With the rise of Daesh in the region, the Obama administration continued its mistakes. First President Obama underestimated the possible impact of Daesh and later, after the capture of the city of Mosul, the administration tried to devise a strategy to defeat the terrorist group. With the Kobani crisis, this time the Obama administration made another critical decision by supporting the YPG to fight against another terrorist organization. It led to the increasing empowerment of the YPG at the expense of other groups on the part of the opposition. By only providing air cover for the YPG, the U.S. helped the Syrian militant group to win battles in northern Syria but continue to criticize the opposition groups for their lack of "reliability" without first supporting these groups. The empowerment of this group led to ethnic tension in the region and tensions in U.S.-Turkish relations. However, despite these problems, the Obama administration continued to support this group at the expense of almost every moderate group until the last days of its power. The mistakes of the Obama administration in Syria will probably be a showcase in disastrous foreign policy making. We recently saw how the Obama administration was wrong to let the Assad regime violate the "red line" when the regime used chemical weapons against the Syrian civilians again. The Trump administration tried to avoid the same mistake from occurring a second time and conducted limited airstrikes against the air base in Syria when the attack was launched. However, this was insufficient for the Trump administration to avoid and fix the mistakes of the Obama era in Syria. Arming the YPG and considering a terrorist organization as the only way to defeat Daesh was another error that the Obama administration committed. And despite the aforementioned problems, the Trump administration seems, at this point, to be adopting policies like those of the Obama administration. The risks of this policy have not disappeared. The YPG is still part of the PKK, which is still a national security threat for Turkey. Nobody believes the Syrian Democratic Forces (SDF) has anything more than peripheral Arab units with a YPG command and control structure. There is still not an exit strategy and there is still the lack of transparency in the U.S. arrangement with the YPG. Under these circumstances, this plan seems very detrimental for the ethnic relations in the region and very risky for the future of U.S.-Turkish relations. There is still time to change this course of action or at least to take precautions and not repeat the same mistakes. [Daily Sabah, May 15, 2017]