The United States is worried about a possible future attack from the Islamic State terror group, but it remains unclear just how much of a threat the radicals pose to the country.
The group has in recent weeks been on the move in Iraq, overrunning vast swaths of territory in the country's north as the militants go on a killing spree. While Kurdish fighters backed by US air power have had some successes against the Islamic radicals, they remain unchecked in neighboring Syria as the United States gears up to hit the radicals in that country as well.
The Islamic State poses a major problem for the United States, which aims to keep terrorism in check a decade after the Sept. 11, 2001 attacks on New York and Washington. The militants' territorial gains have Washington worried that its ultimate nightmare could come true -- that the group could carve out a haven in Iraq or Syria and use it as a staging ground for attacks against the US, much like al-Qaida did in Afghanistan.
But just how much of a threat the group poses at the moment remains unclear. Certainly it would like to attack the US if it had the chance, experts say. But the group has its hands full in Iraq and Syria, and it's unclear just when and if an opportunity to hit the US will present itself.
"When it comes to conducting attacks on the US homeland, there needs to be both will and capability, we're not sure there's certainty on either of those fronts at this point in time, but ... this doesn't mean the group won't develop the desire to strike the US in the future, especially as things escalate on the ground," RAND Corporation associate political scientist Colin P. Clarke told Xinhua.
If the Islamic State did attack the US homeland, it would likely be a major attack on the scale of those on New York and Washington that killed nearly 3,000 people from countries worldwide, he added.
"ISIS won't be satisfied with something perceived as impotent or unspectacular. This is a group that would want to pull off something along the lines of a 9/11 style attack, which could take years of planning," Clarke said, using another name of the Islamic group.
But right now the group is focused on creating a radical Islamic state in Iraq and Syria and wants to continue to hold and conquer territory that will push the group closer to its goal of establishing a caliphate there, experts say.
Meanwhile, the White House is eyeing the situation closely amid critics' contention that President Barack Obama had put the issue on the backburner until it recently boiled over.
Obama this week authorized the use of US drones, which are now reportedly flying over Syria ahead of potential US air strikes against the Islamic State fighters there.
Briefing reporters earlier this week, White House spokesman Josh Earnest said the administration was concerned about the threat posed by the radical group, especially regarding its members with Western passports who have traveled to the Middle East to take up arms alongside the group.
"The risk that's posed is that these individuals who have been radicalized, who have gotten military training and are now battle tested, could return to the US or to other Western countries and carry out terrorist attacks," he said.