Daesh occupied scores of Kurdish villages outside Kobani in September. It slaughtered civilians and drove hundreds of thousands of Kurds from their homes during its merciless advance on the city, which straddles the border between Turkey and Syria.  Read MoreJapan's Abe calls ISIS killing of hostage 'outrageous'  In October, Daesh raised its black flag over Kobani's outskirts. It seemed Kobani would fall. Daesh rained mortars and heavy weapons on Kobani's defenseless victims. Daesh threatened genocide against the Kurds, apostates for supporting the West. Kurdish prisoners, including women, were beheaded.  The brutal battle unfolded before the eyes of the world. International media watched from the hills above Kobani on the Turkish side of the border. Islamic State fighters flocked from across Syria and Iraq to Kobani. The Islamic State's leader, Abu Bakr al-Baghdadi, vowed to make an example of the Kurds and kill them all.  Outgunned and outmanned, The Kurdish People's Protection Units fought heroically to defend Kobani. Kurds from Turkey, including fighters of the Kurdistan Workers Party, joined the battle. So did Iranian Kurds and peshmerga from Iraqi Kurdistan. About 40 percent of Kobani's defenders were women.  Read MoreHow the US and Iran could become BFFs  The Obama administration first turned a blind eye to Kobani's suffering, but finally intervened with air strikes and air-drops to resupply the Kurds.  Today, Kurdish flags fly over recaptured territory. Daesh has finally been vanquished. Kurdish militia are undertaking mopping up operations, ridding Kobani of land mine booby traps.  While nearly 1,000 Daesh combatants were killed, Kobani's liberation took a heavy toll on its defenders. More than 300 Kurds were killed. Many civilians also perished.  Read MoreUS should stop Syria not ISIS: Saudi Prince  The battle for Kobani is significant for several reasons:  The Islamic State's defeat in Syria followed a victory for the Peshmerga in Sinjar, where they defeated Daesh and saved thousands of Yazidis. The Iraqi armed forces is also rolling up Daesh in Iraq's Diyala province.  Despite these battlefield gains, challenges remain. Thousands of displaced persons need assistance resettling to their ruined homes in Kobani. Villages around Kobani are still under control of Daesh. Cooperation between Washington and the Democratic Union Party, which represents Syrian Kurds, is shallow and should expand.  Today Kurds rejoice. The world applauds their heroism — and joins their celebration.  When Daesh's obituary is written, Kobani will be enshrined as the turning point in the struggle to destroy the Islamic State.
The liberation of this Syrian city marks a turning point in the war against ISIS, says David Phillips.