Shipping weapons to the dominant Kurdish party in northern Syria will not solve the strategic problems facing the United States in the Middle East, and could instead make them much worse.
The Democratic Union Party (PYD) has indeed set up an admirable administrative system in the districts it controls, one that promises to tolerate religious minorities and offer a wide range of opportunities to women. But the organization's past and present links to the radical Kurdistan Workers' Party (PKK) make it a dangerous and unpredictable partner in regional affairs.
Turkey deeply mistrusts the PYD, and suspects that it intends to create a safe haven from which PKK militants will be able to resume their armed attacks against Turkish military and police outposts in southeastern Anatolia. Similarly, the Kurdistan Regional Government (KRG) in northern Iraq sees the PYD not only as a potent rival in intra-Kurdish politics but also, and more important, as a threat to the stability of relations between the KRG and the Iraqi central government in Baghdad.
It is true that the KRG sent Kurdish fighters (peshmerga) to assist the PYD's militia in breaking the siege of Kobani during the winter of 2014-15. But this operation was no doubt designed to limit the influence of the PYD and help resuscitate the pro-KRG Kurdish National Council, which has voiced strong objections to the PYD's plan to create an autonomous Kurdish entity along the Turkish border.
Both Turkey and Iran have built bridges to the KRG in recent months, partly to block the expansion of the Islamic State but equally to buttress the comparatively moderate KRG leadership in the face of severe challenges from the PKK and other radical Kurdish movements.
The authorities in Baghdad have accepted these initiatives as a necessary evil in the larger battle against the Islamic State, but worry that closer ties with Turkey and Iran will encourage the KRG to expand its borders at the Iraqi government's expense. Peshmerga commanders took advantage of the advance of the Islamic State to seize control of the contested city of Kirkuk, and Iraqi officials expect that other economically and politically important districts will be sliced off as well.
Iraqi security interests in this way diverge sharply from those of Turkey and Iran, although all three governments stand firmly opposed to the Islamic State. Baghdad sees the KRG's designs to take charge of current and future Iraqi oil production as a direct threat to the nation, and appears willing to build up the PYD as a counterweight to both the KRG and the Islamic State.
Turkey sees things much differently, and has redoubled its efforts to train nominally non-sectarian Syrian fighters as an alternative to the PYD's militia. Ankara is joined in this project by Saudi Arabia, whose leaders have at last recognized the costs of turning a blind eye to the expansion of the Islamic State.
Under these circumstances, the Obama administration's willingness to believe the PYD's protestations that it has no current connections to the PKK or the radical Iranian Kurdish movement the Party for the Free Life of Kurdistan (PJAK) runs counter to the prevailing tide in regional affairs. If Washington decides to join forces with the most violent wing of the Kurdish national movement, which has a long history of armed struggle against the established governments of the Middle East, this step will most likely inflame smoldering tensions between the U.S. and the rest of the anti-Islamic State coalition.