The Obama administration has spent years downplaying the possibility of terrorism attacks on U.S. soil and terrorist strikes in general at the hands of radical Islamists – going so far as to call ISIS a "JV team" at one point – but that calm attitude is fading.
U.S. authorities have quietly raised threat levels and defenses at several American military bases, sent local civilian police agencies on alert and bolstered surveillance at the nation's rails, airports, shopping malls and even energy plants, the Los Angeles Times reported.
The FBI, meanwhile, has arrested 30-plus Americans on terrorism-tied charges just this year, most of whom were seeking to further ISIS plots.
TRENDING: Greatest Show on Earth: The Hur report hearing
James Comey, the director of the FBI, warned just a couple weeks ago "hundreds, maybe thousands" of U.S. citizens are being inundated with frequent recruitment messages from ISIS on Facebook, Twitter and other social media accounts.
He said of the terrorist recruitment campaign: "It's like the devil sitting on their shoulders saying, 'Kill, kill, kill.'"
And Jeh Johnson, Homeland Security Department director, just told an MSNBC viewing audience the U.S. has entered a "new phase, in my view, in the global terrorist threat."
His big concern?
Lone wolf attacks, Jihad Watch reported.
"We have to be concerned about the independent actor and the independent actor who is here in the homeland who may strike with little or no warning," he said. "The nature of this global terrorist threat has evolved."
America's military and intelligence officials are trying to catch up to this new game plan and shift from a strategy of al-Qaida infiltration to one of detection and prevention on home soil.
The Los Angeles Times reported U.S. Northern Command bolstered security at all the nation's military bases in recent times, while more armed guards have been tasked to patrol the federal buildings in the country.
Homeland Security has taken the lead on protecting the nation's transportation systems and crowd gathering points, including malls and sports events, but have tried to keep a low profile.
"Since last summer we have ramped up security at federal installations across the country, and we have increased our outreach with critical infrastructure operators," one senior level Homeland Security official said to the Los Angeles Times.
At the same time, America's military has been reaching out to international allies for help on the global fight against ISIS and other terror groups, and sought clamp-downs on funding outlets.
"It's a long-term challenge," said Brett McGurk, the deputy assistant secretary of state for Near Eastern affairs, in a recent CNN interview. "We have not seen this before. And it's going to take a very long time to defeat them."