The battle for the Syrian Kurd town of Khobane has emerged as an opportunity to deal the Islamic State a military and political defeat. Maximizing the opportunity, however, requires what has been most grievously missing from the struggle against the terrorists and their so-called caliphate: persuasive, coherent and steadfast American leadership.

On Sept. 16, IS fighters attacked Khobane. Capturing the town would have given them direct control of a major Syria-Turkey border crossing. It would also weaken Syrian Kurd resistance by denying Kurd militias a major supply and recruitment center.

Seizing Khobane also served propaganda purposes. From Turkish hills overlooking Khobane, international media would document the IS victory and the Turkish Army’s presence but utter failure to intervene.

But thanks to Kurdish courage reinforced by U.S. airpower, Khobane withstood the initial attacks, withstood repeated assaults by reinforced IS fighters and then bore a sustained siege featuring bitter street fighting.

On Oct. 19, Kurds in Khobane reported that IS fighters retreated. Reporters in Turkey speculated the siege had ended. Not so, Syrian Kurds said, but the terrorists had suffered severe casualties. One source claimed that during the last five weeks, 700 IS fighters have been killed in the area.

The figure strikes me as credible. The extended fight for Khobane forced IS fighters to mass (concentrate combat power) in order to sustain the fight. The IS has tube and rocket artillery and some armored vehicles, but several thousand fanatical fighters are its core combat resource. So the IS massed its manpower.

Until Khobane, the IS has responded to air attacks by dispersing its fighters; IS commanders do not want to give coalition targeteers a concentrated target. In many cases, IS fighters hide in civilian neighborhoods (ie, they use civilian non-combatants as human shields).

Khobane’s location makes it a different case. Anti-IS coalition aircraft had conducted approximately 135 air strikes in and around Khobane. Though the Obama administration continues to reject deploying U.S. ground combat forces, to include ground troops to control and coordinate air strikes, the Turkish soldiers on the northern hills are NATO troops. NATO employs a common doctrine for conducting airstrikes. Turkish Army brigades definitely have tactical air control teams.

The lesson for the Obama administration and its coalition of the less-than-willing: Effective air strikes require close air and ground coordination. Battles for other IS-controlled cities will not have NATO territory immediately next door.

As I write this column, British media report that Syrian Kurds Turkey has allowed them to receive military and medical supplies. Kurd fighters in Khobane are also communicating with the coalition. Given the short distance, all communication requires is a cellphone. Yes, you can use an iPhone to coordinate air strikes.

I see Khobane, another potential military upside. Five weeks of battle consumes a lot of ammunition. The IS relies on captured ammunition as a supply source. The coalition must target IS re-supply efforts.

Khobane also has political effects. The Turkish government publicly refuses to aid the Kurd Democratic Union Party. Turkey argues that the PYD is the Syrian branch of the Kurdistan Workers Party. The PKK has fought an on and off insurgency in Turkey since the early 1980s. Yet there is always a deep story, obscured by plausible deniability. This week, Turkey asked the Iraqi Kurdistan regional government to send a contingent of its peshmerga militiamen to Khobane. Anyway, the U.S. is now airdropping supplies into Khobane.

Yet Khobane is also a reminder of U.S. failure. The Obama administration missed the optimal moment to strike Islamic State fighters. That came — and went — in June as mobile columns of truck-mounted IS fighters left their bases in Eastern Syria and attacked Iraqi positions in Anbar province and Iraqi Kurdistan. “Soft-skinned” trucks in columns moving on desert roads are ideal targets for air strikes.

Austin Bay is a syndicated columnist.