Normally, if one opts not to ignore a foreign-policy problem, the two choices are: Fix it (which in ISIS’s case would mean defeat and destroy it, per America’s official policy), or contain it. The choice is made based on an analysis of the likely costs and risks of eliminating the problem versus those of living with it, as well as the impact of one’s decision on broader concerns. From both points of view, Biddle and Shapiro’s arguments are flawed.
Admittedly the costs of destroying ISIS as a jihadist ideological movement, and its remnants as an insurgency (i.e., what it was in Iraq before 2014), not to speak of “fixing” Syria and Iraq, are just as daunting as Biddle and Shapiro repeatedly argue. But that isn’t, or shouldn’t be, the mission. The mission should be crushing ISIS as a state and as a military and economic power. That is a different challenge, and one far more responsive to conventional military power. Local forces with minimal U.S. indirect support have already made progress in some areas, including recently in Shadadi, Syria, and Ramadi, Iraq. ISIS has fewer foot soldiers than at any time since 2014, and has problems, as the authors note, paying its bills.
A much more robust indirect support package of advisers, artillery, and attack helicopters, more special-operations raids, and even more liberal rules of engagement for air strikes than those just adopted (decentralizing strike decisions, accepting slightly higher risk of civilian casualties, and using more airpower and more powerful bombs) could generate more rapid victories. A limited commitment of U.S. ground troops—two brigades of 5,000 troops each, reinforced by other NATO forces, along with local allies—could make even more rapid progress. These would supplement the 5,000 or so American troops now in Iraq training local forces and the 250 special-operations forces just deployed to Syria. Thus even a tweaking of current U.S. indirect support (now in the works), and certainly limited direct American combat, could destroy ISIS relatively rapidly as a “state” and “army.” That would leave a “day after” problem, but would solve ISIS-as-a-state.
And the U.S., at least sometimes, has effectively dealt with such “days after” without massive American troop presence, from northern Iraq after the Gulf War in 1991, to Kosovo, El Salvador, and Colombia. But even a messy post-ISIS situation is better than containment, given that course’s dangers and costs. It’s those, which the authors largely ignore, that have to be weighed against the costs of destroying the ISIS state.
The costs of containment begin with a huge military campaign, in terms of time (almost two years so far, with no end in sight), forces (thousands of American ground troops, large coalition contributions, hundreds of aircraft, hundreds of thousands of Iraqi regular and Iraqi and Syrian irregular forces), and money ($7 billion so far, with billions more spent by the Iraqis), just to “contain” and slowly degrade ISIS.