Which terrorist group is a bigger threat to the United States, al-Qaeda or the Islamic State (IS)? It almost sounds like the sort of question you’d put to a child comparing movie monsters. But it’s actually the question posed by this recent New York Times article on how the US government is reacting to each of these terror groups. And according to the Times, the allocation of resources to fight each group is hinging in large part on the answer.

Domestic law enforcement authorities such as the FBI and Homeland Security are reportedly more concerned about IS, because of its sophisticated online efforts at domestic radicalization. But intelligence and counterterrorism officials focused on overseas threats see al-Qaeda affiliates as the bigger danger, because they worry the group could capitalize on the chaos in countries like Syria and Yemen to plot “mass casualty” attacks, such as against airliners carrying hundreds of passengers.

What this apparent domestic power struggle over resources doesn’t address, though, is how the United States is fighting each group and whether the extremely costly military piece of that strategy is a smart use of those funds or even legally authorized. It also highlights the absurdity of US officials continuing to insist IS is a “successor” to al-Qaeda that falls within the scope of Congress’s 2001 Authorization for the Use of Military Force against al-Qaeda and the Taliban – the current justification for the US bombing campaign in Iraq and Syria. 

On the one hand, Lisa Monaco, President Obama’s Homeland Security and Counterterrorism Advisor, says IS poses a “unique threat” to the US homeland, even though the group’s main focus is on establishing a caliphate in Syria and Iraq rather than on attacking the West. To the extent the group has sought to incite Westerners to attack within the United States, the FBI, which has reportedly reassigned criminal squads to monitor terrorism suspects, appears to have been extremely successful at thwarting them.

John P. Carlin, assistant attorney general for national security, told the Aspen Security forum that law enforcement officials have made more than 50 terrorism-related arrests in the past 18 months, mostly involving the Islamic State, in 20 different federal jurisdictions across the country. And James Comey said earlier last month that authorities thwarted multiple attacks plotted for July 4 by IS and its sympathizers. He’s also said the FBI has hundreds of investigations pending into IS-related cases across the country.

Of course, FBI investigations and arrests don’t require any special legal authorization. Armed conflict does. The United States has about 3,400 US troops stationed in Iraq to fight IS, and leads a coalition of allies that’s conducted between 5,000 and 6,000 airstrikes in Iraq and Syria in the process, according to Monaco. A new project called Airwars by an independent group of journalists recently reported those strikes have killed more than 450 civilians as well. The Obama administration continues to claim those strikes are legally authorized by the Congressional authorization to fight the Taliban and al-Qaeda issued in 2001, and therefore part of the same war that’s left 9,800 troops in Afghanistan to keep fighting it. Al-Qaeda, meanwhile, hasn’t successfully attacked the United States homeland in 14 years.

Quinta Jurecic at Lawfare noted on Tuesday that the reported death of Taliban leader Mullah Omar is likely to splinter the Taliban further and encourage IS to directly fight the Taliban for control of Afghanistan. Although the US never claimed IS was a successor to, or co-belligerent of, the Taliban, can the US claim one legal authorization to fight two different terrorist groups that are fighting each other?

More importantly, IS and al-Qaeda are clearly different groups that have themselves been at serious odds with one another. The group now known as IS split apart from al-Qaeda in February 2014 after IS killed an al-Qaeda emissary and the latter group formally cut ties. IS has since become even more violent in its attempt to establish a caliphate, and has maintained that extreme violence in large part as a form of competition with al-Qaeda. Indeed, IS is now reportedly beheading people for joining and fighting for al-Qaeda. The two are certainly not co-belligerents in any sense that would allow the United States to claim the authority to fight them as an “associated force” under the authorization to fight al-Qaeda.

None of this is to say that the United States shouldn’t be fighting IS, if it really does pose a serious threat to the United States that can best be addressed militarily. But can it? According to the Times, “American analysts say the Islamic State is replacing its combatants in Iraq and Syria as fast as the United States and its allies are killing them there, and the group still maintains as many as 31,000 fighters.”

This all cries out for some serious re-thinking of how the United States is fighting al-Qaeda, IS and any terrorist threat, using precious taxpayer resources. While the Times reports the White House is reviewing its counterterrorism policy toward the Islamic State, that review shouldn’t just be limited to the White House. How best to fight this worrisome threat – and how worrisome it actually is — calls for a much more open and honest discussion and debate, one that includes lawmakers in Congress and ordinary Americans. But so long as the Obama administration insists it has the legal authority to militarily fight all these terrorist or insurgent groups wherever they exist, and Congress acquiesces, that important debate is not going to happen.