Finally, this Thanksgiving, we have something to be thankful for. Either the Syrian or Russian air force has bombed a Turkish convoy near Azaz and war has finally broken out between the YPG and Syrian rebels in Aleppo province (while the Syrian rebels and YPG are collaborating in destroying the IS in Hasakah province). While the Syrian rebels the YPG is fighting in Aleppo are not IS collaborators (just the contrary, in fact), the Kurdish conquest of Azaz will make the final and total defeat of the IS on the Turkish border much more likely, which is absolutely necessary in cutting off the IS’s supply lines. The Syrian rebels in Azaz are also collaborating with al-Nusra, which, may I remind you, is just as fundamentalist as ever.
The Obama administration has promoted Kurdish expansionism in Syria since October of last year, when it decided to not give Kobani to the IS. It has since sent 50 military officers to aid the Kurds of Hasakah and cis-Euphrates Aleppo province in their fights against the IS. If so, why the previous IS expansion to Kobani in September-October 2014? Perhaps, the Obama administration’s permission of IS expansion in the Kobani pocket in September-October of last year was an attempt to create stronger Kurdish-Arab collaboration to pave the way for future Kurdish expansion. After all, one has a much stronger incentive to turn to territorial expansion and to seek allies if one is feeling threatened by foreign enemies (cf., Israel, 1967). In Spring of this year, Syrian Kurds captured Tell Abyad, an amazing feat of military strength. Kurds are not part of the Axis of Resistance, so U.S. support for them does not contradict its current policy of not overthrowing Assad, but placing AoR forces into a grueling and endless battle against IS and Syrian rebel forces.
-Map of present Kurdish offensives in Syria (yellow arrows show direction, not speed). Map from Wikipedia, a highly reliable source for information on the geography of the conflict since Spring 2013.