Is a US goal of containing the Islamic State advisable?

President Obama endeavored this week to set some realistic expectations for the US approach to countering the Islamic State (IS).

“I would distinguish between making sure that the [region] is perfect – that’s not going to happen anytime soon – with making sure that ISIL continues to shrink in its scope of operations until it no longer poses the kind of threat that it does,” he told ABC News’s George Stephanopoulos, using the US government’s acronym for the terrorist group.

So how pragmatic a goal is it to essentially contain IS? And even if it’s realistic, is it advisable?

Shrinking IS territory is key to countering the IS narrative that it is a caliphate with manifest destiny. That said, “it’s slow-going, and it’s clear to everyone that we’re not making progress as quickly as we’d like to,” says Paul Scharre, a senior fellow at the Center for a New American Security in Washington.

Yet while containment “isn’t ideal for lots of reasons, it’s pretty much unavoidable,” adds Stephen Biddle, professor of political science and international affairs at George Washington University in Washington.

The interview with Mr. Obama was conducted Thursday, the same day that US forces conducted a drone strike in Raqqa, Syria, that is believed to have killed Mohammed Emwazi, the IS terrorist and British citizen known as Jihadi John, who was prominently featured in brutal IS execution videos.

Though senior US military officials say that news is “welcome,” they acknowledge the move was not a tactical master stroke.

“This is significant, of course, because Jihadi John was somewhat of an ISIL celebrity, if you will,” said Col. Steven Warren, spokesman for Combined Joint Task Force Operation Inherent Resolve, in a video briefing from Baghdad with reporters Friday. “So there is certainly I think a significant blow to the prestige of ISIL, but Jihadi John wasn’t a major tactical figure.” 

That said, the US military has “killed, on average, one mid-to-upper-level ISIL leader every two days since May,” Colonel Warren added.

Aggressively attacking IS leadership structure is a key step that the United States has to take to counter IS, says Mr. Scharre, who is a former special operations reconnaissance team leader in the 3rd Ranger Battalion.

The US “must go after their leadership structure, and clearly we’re doing that,” he says. This in turn “degrades their ability to conduct effective operations in the region.”

However, some argue that a containment goal simply doesn’t go far enough – that IS must be destroyed. And many of the GOP presidential candidates, including Ben Carson, have said that destroying IS would be far easier than the president appears to realize.

On this point, Obama took issue in the ABC interview. “Over the last several years, I’ve had access to all the best military minds in the country, and all the best foreign policy minds in the country, and I’m not running for office. And so my only interest is in success.”

Even so, he added, “What we have not yet been able to do is completely decapitate [IS] command-and-control structures.”

One danger of containment is that it leaves the US vulnerable to mission creep.

“The administration isn’t willing, or doesn’t think it can politically sustain a strategy of just staying out altogether. So they do a little, then that doesn’t work, and they change policies and do a little more,” Dr. Biddle notes.

Indeed, since June 2014, there has been “small, incremental escalation, which is often what happens when you try to occupy a middle ground.”

At the same time, the US government should try to tone down the rhetoric surrounding the risk that most Americans face from terrorist attacks, Biddle adds. “Even in the worst year for terrorist attacks in US history – 2001 – more Americans died of peptic ulcers than terrorist attacks,” he says.

Having a more realistic discussion about the threat of terrorist attacks on US soil will make it more feasible for the administration to avoid getting drawn into mission creep, he adds. “Changing the way we talk about these threats in the US makes it easier for people to settle for containment.”

It will require the patience of the American people, since the US will need to keep in place a policy of containing IS “until such time as all parties are mutually exhausted,” Biddle says. That’s a “slow process” that will take seven to 10 years, he estimates.

In the meantime, the US can examine “how do you accelerate that process a bit at the margin” and do it, he adds, “without ending up with a mission creep of 200,000 US troops.”