Kurdish Peshmerga fighters hold a position at a frontline in Yangije, where heavy clashes against Islamic States (IS) fighters took place the previous night. (Jm Lopez/AFP/Getty Images)

The most compelling and encouraging parts of President Obama’s Islamic State speech — his intention to “degrade and ultimately destroy” the enemy, his pledge to hunt down its fighters and deny them “safe haven,” his moral clarity on their “acts of barbarism” — also sounded least like Obama. Everyone — and I mean just about everyone on the planet — knows that he was more comfortable declaring that the United States had moved “off a permanent war footing” and that the war on terrorism, “like all wars, must end.”

This is not merely a statement of the obvious. It illustrates the main problem with Obama’s current approach to the rise of the Islamic State in Syria and Iraq. His newly announced policy consists mainly of previously discarded policies that would have been easier to pursue in the past: Supporting moderate rebels in Syria. Asserting executive authority to bomb on both sides of the border. Actively cooperating with Iraqi and Kurdish forces to build their capacity.

It is reasonable to question the level of Obama’s enthusiasm for a series of options he has previously ignored, dismissed or even mocked. (It wasn’t long ago — actually about five weeks — that he called proposals to arm the Syrian rebels the outgrowth of a “fantasy.”) Tim Arango, the New York Times Baghdad bureau chief, recently observed: “After 2011, the administration basically ignored [Iraq]. And when officials spoke about what was happening there, they were often ignorant of the reality.” This was the period in which al-Qaeda in Iraq — then seriously degraded — began to recover, gained a foothold in Syria, changed its name, attracted jihadist recruits, gained battlefield experience and resumed the offensive.

So Obama’s policy shift is late. For this reason, it has a reduced chance of success. It has, so far, attracted a distressingly small coalition of the willing. But the essence of the policy is reasonable.

In his speech, Obama correctly identified some of the most important lessons of 9/11. First: Disrupt the immediate terrorist threat — particularly the thousands of jihadists in Syria and Iraq (hundreds with U.S., European or Canadian passports) who might attack targets in the West. They present a short-term prospect of violence — a mass shooting or a bomb on a busy street. (And they are not alone, since various al-Qaeda-related groups, particularly al-Qaeda in Yemen, have continued to plot against U.S. targets.)

A second lesson: Prevent the scale of the threat from growing in territorial havens. From the time that Osama bin Laden gave the go-ahead for his hijacking plan, it was more than 2½ years until the complex, coordinated attacks of 9/11. Large-scale violence generally requires training, time and a base of operations. The United States’ goal is to keep terrorist leaders harried, moving and fearful for their lives — unable to do their day jobs, which includes planning spectacular acts of murder. Territorial havens magnify the terrorist threat.

The United States has successfully implemented this type of strategy before. Following 9/11, U.S. forces drove al-Qaeda out of its camps in Afghanistan. Intelligence operatives pursued its leaders to safe houses in Pakistan. After a few years of building up its intelligence capacity, the United States found ways to track and strike terrorist leaders in Pakistan’s remote Federally Administered Tribal Areas.

Obama now has an even more difficult job. It should be possible, over time, to increase the capabilities of Iraqi and Kurdish forces (forces that are numerically superior to the enemy) and roll back the gains of the Islamic State in northern and central Iraq. Both the Iraqi army and the Kurdish pesh merga were initially unprepared for a battle-hardened opponent — but might, conceivably, be made prepared with sufficient U.S. support and training.

The worse problem lies in Syria. Rolling back a haven is not done from the air alone. And the forces on the ground are either weak (the moderate rebels) or directed by a war criminal and Iranian puppet (Syrian government forces). Obama has correctly ruled out a rapprochement with Bashar al-Assad. But there are serious questions about the capacity of moderate rebels eventually to hold a Syrian state together.

Suffice it to say, the U.S. campaign in Iraq and Syria will take years and hit major obstacles: lack of intelligence infrastructure, disappointing allies, badly flawed options in Syria. It is one thing to have a strategy; another to pursue it with creativity and absolute resolve. And there is basis for skepticism in Obama’s hedged and careful war.

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