Could Islamic militants in Iraq bring their fight to America?

As the Islamic State gains ground and enlarges its pool of foreign fighter recruits, it is increasingly likely to attack on American soil as well. 

That has been the warning coming from some lawmakers and defense analysts this week, who argue that the United States has de facto declared war on the Islamic State by launching air strikes against IS positions, and now it must steel itself for foreign militants to bring the fight to the US.

“Mr. President, be honest with the threat we face,” Sen. Lindsey Graham (R) of South Carolina warned on Fox News. “They are coming.” 

Senator Graham’s warning followed what seemed to be an Islamic State fighter threatening to “raise the flag of Allah in the White House.”

A widely-circulated photo on the web showed an IS supporter taking a photo with an IS flag in the foreground, and the White House in the background, the implication presumably being that the IS was at the gates of the White House. The tagline on the much-discussed but unverified photo read, ‘We r here,” with a smiley-face emoticon. 

There is, however, a big difference between aspirations of attacking America on its own soil and having the means to carry it out. Do IS fighters have skills or means that surpass, for example, Al Qaeda, who has been threatening for more than a decade after 9/11 to carry out another significant attack on US soil, but never managed to do it?

“These [IS] guys are battle-hardened, and they have had a significant amount of training in Syria and Iraq on all kinds of tactics and techniques, like bomb-making,” says Samuel Brannen, senior fellow in the International Security Program at the Center for Strategic and International Studies.

“They have blood on their hands – not just read about it on the Internet,” he adds. “That is something they have now done – fired a gun at a human. It’s not about bringing new skills, but practiced skills.” 

What’s more, increasing numbers of IS fighters are Westerners, California Sen. Dianne Feinstein and others have warned. “They are not applying for visas,” Mr. Brannen says. “They are showing passports.” 

This will likely mean higher bars at US borders and stepped-up intelligence sharing with Turkey and other NATO nations. That said, Brannen adds, “It could be really tough.” 

At the doomsday end of the spectrum, some analysts argue that the combination of Western-born fighters and IS ambition could create “an existential threat” to the United States. 

“This could happen in the broadest sense of the term,” says retired Col. Peter Mansoor, former executive officer to retired Gen. David Petraeus, who commanded US forces in Iraq.

“It would initially take the form of terrorists coming back to the United States from Iraq and Syria using their Western passports and conducting horrific terrorist acts on the homeland,” adds Dr. Mansoor, now an associate professor of military history at Ohio State University. 

“In the longer term, if [IS] would be able to get control of the kinds of lands that they seek – the Islamic world as it was in the 11th century, which includes Spain, Pakistan, and Iran – they would also seek to gain control of nuclear weapons,” he adds. “I have no doubt that if this group gained control of a nuclear weapon that they would use it, and they would become an existential threat to the entire Western world.”