On September 22, the air campaign against ISIS expanded into Syria in a coordinated attack that included 47 Tomahawk missiles and nearly 50 coalition aircraft. This action had been all but inevitable since the commencement of overflight reconnaissance in Syria on August 26. Significantly, these strikes also included targets of the Khorasan Group, an al-Qaeda affiliate unrelated to ISIS. Also significantly, five Arab militaries—Bahrain, Saudi Arabia, the United Arab Emirates, Jordan, and Qatar—participated in the operation. At this stage, there are three important questions to address: the targeting of the strikes, the implications of this action, and potential challenges that might await the operation moving forward.

What was hit?

The primary targets of the initial bombing in Syria were ISIS training bases, military vehicles, headquarters, and resupply facilities. These were clustered in the Islamic State’s de facto capital of Raqqa. Although the Pentagon is in the midst of a battle damage assessment (BDA), officials have stated that initial reports suggest a high strike effectiveness. Preliminary estimates place the number of ISIS fighter casualties at a minimum of 70—and likely more. 95 percent of expended munitions were precision-guided, suggesting a clear awareness of the strategic peril of unconstrained bombardment and collateral damage. This also marked the first combat deployment of the F-22 Raptor (watch the gunsight video here).

(Related: F-22 Finally Makes Its Combat Debut Against Syria)

It is important to distinguish the “hard target” strikes against ISIS from the targeting of high-value individuals that has often characterized the global war on terror. Unlike most “traditional” terror networks, ISIS has amassed significant amounts of conventional military equipment, including U.S. made equipment abandoned by the Iraqi army that they have been putting to good use. Destroying these stationary targets, along with training sites, supply and munitions depots, etc, will significantly degrade ISIS’s ability to conduct lethal military operations.

For many Americans, this will be their first time hearing of the Khorasan Group, a small group of roughly 50 “seasoned al-Qaeda veterans” who had based themselves amid the chaos of the wider Syrian Civil War in order to plot attacks beyond the region. The decision to include strikes against Khorasan with the wider anti-ISIS effort was based on intelligence about an “imminent,” spectacular attack, to take place in either the United States or Europe. Eight Khorasan targets were destroyed in the bombardment.

What are the wider implications?

Most immediately, the enlargement of the anti-ISIS campaign’s zone of operations demonstrates an understanding that ISIS has long been twisting international boundaries to its own advantage. As one senior White House official stated in a September 23 media call, “We’re fighting an organization that operates irrespective of borders—we have to look at it that way.” It is a worthwhile question, however, if a quicker expansion into Syria might have been more strategically impactful.

The conduct of these strikes also shows a keen awareness of the optics of the whole anti-ISIS effort. Even a 26-nation coalition will be insufficiently compelling if it remains constrained to paper. The Pentagon was careful about not revealing exactly which regional nation conducted what parts of the military operation, saying that it will be up to each partner nation to make such announcements. Regional partners should be as open as possible about their support and contributions in order to refute the perceptions that this is an American-only effort. The visibility and active participation of these nations will be critical in stemming and rolling back the ISIS threat.

(Read More: Air Strikes in Syria Are 'Only the Beginning')

Domestically, there is now broad-based American public support for strikes against ISIS, likely prompted by the resonating impact of the James Foley and Steven Sotloff execution videos. 79 percent of Americans reported in a CBS News/New York Times poll conducted September 12-15 that they viewed ISIS as either a major or minor threat. 71 percent favored air strikes against ISIS in Iraq; 69 percent supported expansion of air strikes into Syria.

What are the questions to ask moving forward?

The effort against ISIS has now expanded enough to have a substantial effect on ongoing debate over the FY15 National Defense Authorization Act and the Overseas Contingency Operations account (the means through which ongoing operations are funded). Although anti-ISIS air strikes had cost an average of $7.5 million per day through August, recent events suggest a considerable escalation. Consider, for example, that the fully burdened cost of a new Tomahawk cruise missile is roughly $1.6 million. Gordon Adams, professor of U.S. Foreign Policy at American University and a specialist in defense budgeting, has suggested the costs of anti-ISIS operations could climb as high as $1.5 billion monthly.

If the anti-ISIS coalition’s mission enlarges further, it will also become increasingly necessary to consider the laws by which this use of force has been authorized. On September 22, the White House sent two War Powers reports to Congress: one for actions against ISIS, the other for actions against the Khorasan Group. The U.S. military is currently operating against ISIS under the powers granted by the 2001 Authorization for Use of Military Force (AUMF) that authorized operations against the original Al-Qaeda network and affiliates.

Finally, it must be asked how the anti-ISIS coalition can transition from simply stopping the Islamic State’s momentum to ultimately destroying it. In order to achieve this broader objective, there must be locally-designed and implemented economic and political initiatives that accommodate the myriad interests and drivers of conflict in the region.

These efforts must be actively led by the leaders in the region. The United States may be able to support and coordinate the fight against ISIS—but it cannot unilaterally, nor through purely military means, defeat the terrorist group or bring lasting stability to the region.

Emerson Brooking is a research associate for defense policy at the Council on Foreign Relations.

This post appears courtesy of CFR.org.