We agree that stabilization is too expensive. But we disagree with Jeffrey on the merits of a smash-and-leave conventional offensive. In our view, such a policy actually secures none of the interests that nominally motivate it.

Jeffrey’s argument is a variation on a theme that is increasingly prominent among analysts frustrated with the long U.S. counterinsurgencies in Afghanistan and Iraq: The United States should adopt a policy of waging decisive conventional warfare against states without worrying overmuch about what happens afterwards when the target regime is toppled. But this position isn’t actually new—it represents a return to the de facto policy the United States adopted in Iraq in 2003 and Afghanistan in 2001. A decade later we know quite a bit about the likely consequences, and they aren’t pretty.

If all we’re going to get is the kind of chaos that typically follows regime change without stabilization, such as the kind of warlord governance that we now see in Libya, for example, then the real payoff to smash-and-leave conventional warfare of this type is very limited. Reasonable people can differ on whether the limited payoff and ugly aftermath of U.S. conventional warfare against ISIS is worse than the limited payoff and ugly interim of containment—this is ultimately a value judgment on balancing current against future costs, and different people will have different time preferences on costs. But this is not a simple choice between decisive victory against ISIS as opposed to chronic terrorism with containment. The real difference is much narrower, and we’re going to be living with some version of containment against most of the threat for a long time either way. The greater cost of proposals such as Jeffrey’s thus needs to be weighed against a properly modest understanding of their real benefits.

Jeffrey’s proposal raises at least two important, related, issues for public debate: Is it really wise to topple regimes then leave, and how do we draw the line between threats we must actually defeat and those we will instead contain?

What’s Left Behind by “Smash and Leave”?

As for the first, the smash-and-leave approach fell into disfavor after 2003, when post-Saddam Iraq fell into chaos after the United States failed to stabilize the leaderless country. As early as 2004, Rumsfeldian willingness to dismiss the messiness of freedom in the aftermath of U.S.-imposed regime change was widely criticized as short-sighted. This critique became something like conventional wisdom after the growing Iraqi insurgency drove Rumsfeld from office and led to the surge of some 30,000 additional troops into Iraq in 2007-2008.

Yet the smash-and-leave thesis is now making a comeback. Recent books by retired General Daniel Bolger, retired Colonel Gian Gentile, and by the Reagan administration official Bing West critique nation-building as a military mission and advocate conventional warfighting to destroy hostile armies instead. Israeli analysts bemoan the indecisiveness of occupation and stabilization, and seek a return to the “battlefield decision” of the conventional wars Israel fought in 1956, 1967, or 1973. Many would like some alternative to the Hobson’s choice between mere containment and the long, grinding commitment of stabilization. Conventional invasion followed by quick departure looks to some like an answer.