The rise of ISIS (the Islamic State of Iraq and Syria) took much of the world by storm. In a 2014 interview with the New Yorker, President Obama pronounced the blood-spattered theocratic gang to be no more than a “JV squad” (compared with the varsity squad, al Qaeda) with limited capacity to fulfill its mad totalitarian vision. Within the month, ISIS’s blitzkrieg sacked Falluja and would soon conquer fully a third of Iraq in addition to bulldozing its border with Syria. By June 2014, Iraq’s well-equipped but inept army abandoned Mosul, the country’s second largest city, in the face of the ISIS onslaught. The caliphate was born.

Many observers greeted this self-declared Islamic empire as a new enemy, and its control of a nation-state did indeed set it apart from its predecessors. But, to a great extent, ISIS is an old enemy that became a new one. As Michael Weiss and Hassan Hassan remind us in the most searching examination of the Islamic State to date, ISIS: Inside the Army of Terror, “the United States has been at war with ISIS for the better part of a decade under its various incarnations,” i.e., al-Qaeda in Iraq, (AQI).

What happened to Al-Qaeda in Iraq is revealing because in the record of its undoing lies a plausible approach to vanquishing its successor. By 2010, AQI was “dead on its feet,” as terrorism expert Michael Knights told Congress in 2013. Years after the U.S. surge and the “Anbar awakening” routed al-Qaeda in Iraq, however, two events resurrected this lifeless enemy.

First, the Assad regime in Damascus incited civil war by crushing pro-democracy protests. The Syrian revolt devolved into a clash between Bashar al-Assad’s brutal mukhabarat state and ruthless, highly-organized jihadist bands that created an opening for ISIS. Meanwhile, after the United States withdrew its military forces and diplomatic heft from Iraq, the Maliki regime reverted to the cruder instruments of sectarian rule. The corrupting effect of majority Shia tyranny hollowed out the Iraqi army, which eventually ceded territory to a considerably smaller force of Sunni holy warriors fighting under the banner of ISIS.

At its two-year mark the so-called caliphate retains wide swathes of territory and holds millions of people in bondage. Although it has suffered battlefield reverses, so far these defeats have been tactical, not strategic. Even after thousands of its fighters have been eliminated by an American-led air campaign, ISIS still boasts far more fighters (roughly 20,000) than al Qaeda had at its peak. Even after it has lost nearly half of the territory it previously held in Iraq and Syria, ISIS has created at least six functioning militias outside its homeland. ISIS “provinces” have been established in Libya, Egypt, Nigeria, Saudi Arabia, Yemen and Afghanistan.

ISIS’s state-building project has motivated a new generation of aspiring jihadists. Recruits have flocked to the Euphrates River Valley and undertaken their own franchises in anarchic Muslim lands. What’s more, they have also used the levers of social media communication to declare their support and solidarity for ISIS and encourage “lone-wolf” (or, better put, “self-starter”) attacks on western soil.

The fact that ISIS does not pose an “existential threat” to the United States does not mean that it cannot wreak havoc on the global order. In November 2015, President Obama boasted that ISIS was “contained” a day before its agents slaughtered 130 people in Paris. White House official Ben Rhodes then declared that “there’s no credible threat to the homeland at this time.” This reassurance came after the Garland, Texas attack on a “draw Mohammed” contest and the Chattanooga shooting that killed four Marines and a Navy sailor – and before the San Bernardino attack that killed 14 people, and before Orlando, where 49 people were slaughtered in a gay nightclub. If this grisly pattern is any indication, there is good reason to believe that the power of ISIS’s example will outlive it. This is why it is crucial to diminish ISIS’s ability to market the worst of their brutality on social media, where the caliphate exerts its most powerful draw.

But first the black flags have to be furled in Raqqa. This outcome seems unlikely without a decisive change in strategy. As ISIS implemented its genocidal program in earnest and as ISIS-inspired agents launched mass-casualty operations around the globe, the Obama administration reluctantly availed itself of airstrikes and Special Forces raids, but not a cohesive strategy to address the root causes of the regional meltdown.

The conditions that birthed ISIS – the civil war in Syria and an overtly sectarian regime in Baghdad, both of which inflamed Sunni grievances – have been left to fester. In Iraq, the failure to check Iran and its Shiite proxies have allowed ISIS to offer itself as the defender of last resort to an embattled Sunni minority. In Syria, the failure to depose Bashar al-Assad from power and prevent an ever-worsening vortex of violence is likely to be judged harshly by history. 

A better strategy would act to secure legitimacy in the Sunni heartland of Iraq and Syria. Although this may entail more “boots on the ground,” this seems a moot point when President Obama has already dispatched more than 4,000 soldiers to Iraq. According to reports, U.S. military leaders are preparing requests for more troops and equipment in order to tighten the noose on ISIS. If the president is serious about his avowed objective of “degrading and defeating” ISIS, this is his moment to show it.

The rampant jihadist scourge across the Middle East is, to borrow from St. Augustine, so old and so new. For all of its technological savvy and its theatrical savagery, ISIS represents a familiar foe. But victory will not come easily, and not before taking the full measure of the enemy.