Obama has a plan for ISIS in Syria. It’s the opposite of his old plan.

In his Wednesday night address debuting America's new war against the Islamic State in Iraq and Syria (ISIS), President Obama is going to totally reverse his administration's longstanding Syria policy.

It won't be billed as such, of course, but we know what's coming. Since the war's outbreak in late 2011, Obama has resisted both airstrikes in Syria and any major effort to arm-and-train the moderate Syrian rebels. But advance accounts of the President's speech say those two measures — a bombing campaign and arming the rebels — are at the heart of his new policy for countering and eventually defeating ISIS in Syria.

Why the flip-flop? The obvious answer is that ISIS has gotten stronger, so the administration has decided it needs to use more force against the group. That's part of it. But, to a certain extent, the administration's policy is as much an ad-hoc response to events as it is about a rational assessment of what the US can do to defeat ISIS. The rapid growth of ISIS since June has forced Obama into a policy he's long believed would fail.

Obama doesn't really think his Syria policy will destroy ISIS

A Syrian rebel stands in the street in Aleppo. (Ahmed Deeb/AFP/Getty Images)

The administration's longstanding position has been that ISIS's Syria presence is a problem, but not one that the US can solve through military force. As recently as August 8, Obama downplayed the idea that arming supposedly moderate Syrian rebels — most notably those under the banner of the Free Syrian Army — would help to build a strong fighting force.

He told the New York Times that "there's not as much capacity as you would hope" for molding an effective group out of "an opposition made up of former doctors, farmers, pharmacists and so forth." The administration actually did propose spending $500 million in late June to arm and train the rebels as a counterweight to ISIS, but very few people believed that would be enough help to make the rebels competent to destroy ISIS.

And as for airstrikes in Syria, he said in August that "we can run [ISIS] off for a certain period of time, but as soon as our planes are gone, they're coming right back in" without an effective local partner. There haven't been any dramatic events in the past month on the ground in Syria that would change this assessment — the situation is still fundamentally the same.

But he's been pulled in anyway

Kurdish peshmerga commander Shirvan Barzani (C) after retaking the town of Makhmur from ISIS. (Ahmet Izgi/Anadolu Agency/Getty Images)

So why is Obama escalating in Syria anyway? Two major reasons: ISIS's advances in Iraq and the group's killing of two American journalists.

After ISIS swept northern Iraq in mid-June, administration concern over ISIS ramped up. According to the Wall Street Journal, the late June plan to arm Syrian rebels was a direct response to the crisis in Iraq. ISIS was using Syria as a launching pad for its move into Iraq, so the group needed to be countered in both countries if it was to be countered at all.

Then, in August, ISIS launched a significant offensive against Iraqi Kurdistan. The administration saw Kurdistan as a stable oasis in chaotic northern Iraq, and the fact that ISIS was making inroads there terrified them. So they launched airstrikes to roll back ISIS's gains, which quickly expanded to airstrikes supporting both Iraqi government and Kurdish forces.

The US military effort was, for a time, limited to Iraq. But ISIS's brutal slaughter of two American journalists, James Foley and Steven Sotloff, was the last straw. ISIS announced the murders were punishment for America's bombing campaign in Iraq. The administration was furious.

Once the administration decided to destroy ISIS, escalation in Syria became a fait accompli

After the Foley and Sotloff murders, Team Obama's rhetoric escalated considerably. The administration's previous emphasis on the need for a local political solution to the ISIS problem transformed into a commitment to defeat ISIS.

Both Secretary of State John Kerry and Martin Dempsey, Chairman of the Joint Chiefs, said ISIS must be destroyed. Secretary of Defense Chuck Hagel called them an "imminent threat to every interest we had." Vice President Biden pledged to "follow them to the gates of hell." And Obama himself declared that his policy was to "destroy and degrade" the group.

Once the administration decided to destroy ISIS, escalation in Syria became a fait accompli. It's obviously impossible to eliminate ISIS without taking it on in both Iraq and Syria. Obama — correctly — believes airstrikes alone can't destroy ISIS without local allies on the ground capable of taking and holding ISIS positions. Since the administration can't really coordinate with ISIS's other enemies — al-Qaeda in Syria or Bashar al-Assad's murderous government — the only option left are the so-called moderate rebels.

So the only policy that has even a theoretical chance of accomplishing Obama's new objective in Syria is a combination of bombing ISIS positions and aiding moderate rebels. But that's a policy that the president has, for a long time, said was doomed to failure.

Watch President Obama evolve throughout 2014 on ISIS in under 3 minutes:

Contributions are a key part of the future of Vox

Readers rely on Vox for clear, nuanced coverage that not only illuminates the issues, but poses solutions, too. And we rely on help from our readers: Advertising and grants cover the majority of our costs, but we count on contributions to help us close the gaps in our budget. In fact, we’re looking to reach 95,000 individual contributions before the end of the year. Will you make the next contribution right now? Our average gift is just $20 — and it goes a long way in helping us keep our work free. Vox is here to help everyone understand what’s shaping the world — not just the people who can afford to pay for a subscription. We believe that’s an important part of building a more equal society. Join that mission by making a contribution today.

One-Time Monthly Annual

$5/month

$10/month

$25/month

$50/month

Other

$

Yes, I'll give $5/month

Yes, I'll give $5/month

We accept credit card, Apple Pay, and Google Pay. You can also contribute via