Analysis & Opinions - Belfer Center for Science and International Affairs, Harvard Kennedy School

Ash Carter’s Lessons from ISIS for Israel’s Campaign Against Hamas

| Oct. 25, 2023

Our colleague and friend Ash Carter left us one year ago this week. As we reflect on all he brought to our lives and our nation, and face the challenge Hamas’ vicious terrorist attack that killed 1400 innocent Israelis, it is instructive to consider what the architect of President Obama’s strategy to defeat ISIS might say if asked how Israel should respond. Netanyahu has declared that Hamas is ISIS, and we will defeat it just like the enlightened world defeated ISIS.” While noting important differences between ISIS and Hamas, I suspect he would have taken this invitation to restate lessons learned from our own campaign against ISIS.

Fortunately, Ash not only developed a strategy for defeating ISIS but then subsequently described it in a Belfer discussion paper released in September 2017, shortly after the Obama administration handed off the ISIS fight to the newly-elected President Trump. At the time he wrote the paper, the fight was unfinished but had reached an inflection point: ISIS had just surrendered Mossul in Iraq and would lose Raqqa in Syria three months later, the two cities labeled as “red arrows” through which toppling ISIS ran. By the end of the year, Iraqs president had declared victory against ISIS, prompting Secretary of Defense Jim Mattis to proclaim that “the caliphate is on the run.” Today, ISIS retains only 3,000 fighters and conducted only a single operation in 2023, a shadow of the organization that as recently as 2015 had a $1 billion payroll, 30,000 fighters, and ruled an area of 12 million people.

The strategy for defeating ISIS was developed in close partnership with Chairman of the Joint Chiefs Joseph Dunford.  While his 2017 Belfer report is now six years old, as the Netanyahu government now contemplates launching a full-scale ground invasion to destroy Hamas, three key lessons from the strategy Carter and Dunford crafted offer wise advice.

First, as a sign hanging in the Pentagon reminds us, hope is not a plan. Strategies that lack a clear end state or coherent means to reach it are more aspirational than actionable. When Ash became Secretary, he lamented that officials frequently spoke of the need to “degrade and ultimately defeat” ISIS without conceptual clarity about what any of that meant. Instead, Ash posed the question: could the US live by coexisting and containing ISIS? He decided no, and that an enemy like ISIS, violent and without conscience, had to be defeated.” As a result, he settled on a new goal: lasting defeat, with three core pillars: “dealing ISIS a lasting defeat in its homeland of Iraq and Syria, eliminating the cancers parent tumor; combatting metastases in places like Libya and Afghanistan; and protecting our homeland from ISIS terror.”

To reach this end required a set of clear and feasible ways and means, which meant scrapping the preceding Pentagon’s typical nine “lines of effort” that he dismissed as “a list and not a strategy.” Instead, Ash’s strategy began with two “big red arrows” pointing to the strategic strongholds Mosul and Raqqa and, before that, the Q-West airfield that ISIS relied on for supply lines. To attain those objectives required means or “accelerants”: sending in special operators, deploying aircraft for anti-ISIS missions, plus the training and empowering of local forces to serve as the tip of the spear for our operations. And to ensure this was a lasting defeat meant a sustained counterterrorism campaign aligned with local military forces.

As Netanyahu embarks on his own version of an anti-ISIS campaign, he would be well-served to remember General David Petraeuss prescient plea: “Tell me how this ends.” Having already decided that the mission is lasting defeat” and not containment or deterrence, it falls to Netanyahu to align this end with sufficient ways and means. Ash would likely want to know what Gazan strongholds must be breached to consider Hamas defeated, and what capabilities can Israel marshal, at acceptable cost, to neutralize the “Gaza Metro” of tunnels from which Hamas can emerge and launch surprise attacks.

Second, having a strategy to win the peace is at least as important as a strategy to win the war. As the US discovered in Iraq and Afghanistan during the War on Terror, ejecting the bad guys from power is not the hard part; keeping them out is. Applying this history to the ISIS fight, as Ash put it: “I had no doubt that our troops could have marched into Raqqa and Mosul and ejected ISIS…but to do so would have been a strategic blunder…A defeat of ISIS by US force of arms would be fleeting unless communities taken from ISIS could rebuild and secure themselves.” As a result, priorities one, two, and three were our partners: to train, to equip, and to empower the local fighters who would not only defeat ISIS but also replace them as leaders in the liberated territories.

In designing the post-war plan, Ash cautioned against “vision blindness” that aspires to some final resolution. In the real world, “eternal vigilance is the price of liberty.” While post-ISIS governance was handed off to partners, the US retains a counterterror presence in the region of 3,000 troops in Iraq and Syria to this day and an active campaign 24/7 searching for—and taking off the field—ISIS and their affiliates who are plotting or preparing attacks on the US and allies. While warriors can prevent terrorists from operating secure headquarters or training camps, they cant stop successors attempting to create new headquarters and training camps. While groups cant be prevented from having leaders, sophisticated operations can ensure theyre not long-lived.

Ash would urge Netanyahu to think beyond the understandable first step—eliminating Hamas—and consider: what comes next? Who will govern in the aftermath? ISISs birth from the ruins of Iraq and Hezbollahs emergence after the ejection of the Palestinian Liberation Organization from Beirut are stark reminders that extremism thrives in leaderless Middle East vacuums.

Third, the best-laid strategies will fail if not sustainably resourced at home. As Ash considered how best to take the fight to ISIS, he faced an immutable constraint: Americans’ lack of appetite for another “forever war” in which their countrymen would be sent to die in foreign lands. He noted that “The president clearly wanted to reassure the American people that we were not involving ourselves in large-scale ground combat, and the people of the region did not want invasion-sized forces to return.” Operating within these parameters stretched Pentagon planners’ imaginations and required adjustment: pursuing goals by “identifying and enabling local Syrian and Iraqi troops to lead the fighting by leveraging a relatively small footprint of US and coalition forces.”

While a sustained campaign to eject Hamas from Gaza is militarily feasible, Ash would likely ask Netanyahu to think about its politically feasibility? Will Israelis sign up for a multi-month (or year) campaign that brings weekly reports of more sons and daughters killed in brutal urban combat? If an extended war in Gaza becomes the provocation or pretext for a multi-front war, can Israel’s military, economy, and society sustain that war? Clues from the way the Obama team worked to “demonstrate that ISISs mere existence could inspire enough hatred to endanger the safety of the American people” may be helpful. Given Gazas presence on Israels border and the vivid nature of the threat, it may be easier to sustain such a consensus.

As these events unfold, all of us have more questions than answers, and Ash would have been no exception.  But as we struggle with the current challenge, we need his insights and pointers about what led us to where we are now—and where we go from here.

I had the great fortune to know Ash as an academic colleague, Pentagon counterpart, and thinker who was unafraid to ask the big questions, but, most valuably, as a cherished friend of forty years. We miss him dearly—but fortunately we can still look back at his wisdom and learn.

Read Ash Carter's 2017 report:  A Lasting Defeat: The Campaign to Destroy ISIS






For more information on this publication: Belfer Communications Office
For Academic Citation: Allison, Graham.“Ash Carter’s Lessons from ISIS for Israel’s Campaign Against Hamas.” Belfer Center for Science and International Affairs, Harvard Kennedy School, October 25, 2023.