News Analysis: U.S. enters new phase of war of terror, with no clear way to fight it

The United States has entered a new phase in the fight against terrorism as radicals are increasingly using the Internet to recruit people to carry out attacks on American soil, but Washington has yet to find a clear way to fight it.

In an interview with ABC News on Sunday, U.S. Secretary of Homeland Security Jeh Johnson said the Islamic State (IS) is exerting its influence in the United States via the Internet, far from its home base in Syria and Iraq.

"We're very definitely in a new phase in the global terrorist threat, where the so-called lone wolf could strike at any moment," he said, adding that the IS' effective use of social media and the Internet has the ability to reach the U.S. soil and possibly inspire others.

Several weeks ago, two gunmen in the U.S. state of Texas opened fire on a contest to draw cartoon images of Prophet Muhammad.

Any depiction of Muhammad is considered blasphemous in Islam. The IS and other Islamist extremists believe it is a crime punishable by death.

There is growing evidence that the IS had direct contact with gunmen Elton Simpson and Nadir Soofi, who were killed by police.

But it remains unknown what steps the United States will take to thwart any future attacks directed from abroad. Certainly, such attacks are difficult to stop, as U.S. authorities cannot monitor all Internet traffic and social media. Moreover, there will be some pushback from rights groups who object to too much government watchfulness on the general population.

Speaking on Fox News on Sunday, Chairman of the House Homeland Security Committee Michael McCaul said terrorism has "gone viral." Spotting such threat is like finding a needle in a haystack sometimes, he said.

"I think the threat environment is the highest I've ever seen," he said when asked how the threat stacks up to 9/11, citing a number of failed states worldwide and the ability for terrorists to radicalize people via the Internet.

U.S. media reported last month that six men were arrested in the U.S. states of Minnesota and California on suspicion they tried to travel to Syria and fight for the IS, although the U.S. Attorney's Office in Minnesota said they posed no threat to the public.

And in February, FBI agents arrested three men in New York for plotting to join the IS. All three were charged with conspiracy to provide material support to the extremist group.

FBI Director James Comey warned last week that there are potentially thousands of people in the United States consuming what he called "poison" from the IS online, explaining that it is very difficult to identify and stop anyone inspired to launch an attack inside the United States.

"The administration finally admitted that it took the IS too lightly," James Phillips, a Middle East expert at the Heritage Foundation, told Xinhua.

Indeed, President Barack Obama initially downplayed the IS threat before it boiled over and became impossible to ignore.

Obama said several months ago that he would focus on tackling radical ideologies, but since then has said little on the matter. "The president has over-promised and under-delivered," Phillips said.

"The administration has identified the problem as 'violent extremism,' which is a politically correct euphemism. Until the administration admits that the problem is Islamist extremism, its counter-radicalization efforts are likely to be hamstrung by political correctness," he said.

It is necessary for policymakers to consider the factors that push people over the edge and cause them to commit violent acts or provide support to attackers, said Colin Clarke, associate political scientist with the RAND Corporation. Endi