The White House waited five days after the shooting rampage that killed five servicemen in Chattanooga, Tenn., before lowering the flags on federal buildings to half-staff.

It took the administration more than five years to describe the 2009 Fort Hood massacre as domestic terrorism rather than "workplace violence" and grant the victim purple hearts, a designation of honor reserved for combat wounds.

Critics say both delays demonstrate a lukewarm, less-than-urgent response from President Obama to the domestic terror threat amid a surge in Islamic terror activity over the last year, which has seen the rise of the Islamic State and the group's barbaric march across the Middle East. The flap over the flag quickly became the latest example of how the White House is slow to react to these events when they happen.

Asked why the White House waited five days after the Chattanooga shootings to lower the flags on federal building, and only after Congress had already done so, a spokesman said he didn't have a good explanation.

"I don't have a lot of insight to provide to you in terms of that decision-making process other than to note that it's a decision that was made and announced yesterday," White House spokesman Josh Earnest said Wednesday.

The lack of a rationale gave critics an easy opening to step in with a broader critique of how the U.S. is dealing with the larger issue of domestic terrorism.

"I believe we are losing on both fronts in this war against Islamic terror," Rep. Mike McCaul, a Texas Republican who chairs the Homeland Security Committee, said Wednesday in a speech at the Heritage Foundation. "Our enemies have the momentum and they have thrown us off balance — the numbers don't lie … by any measure we have failed to turn the tide against them."

America now faces the most serious terror threat environment since the Sept. 11, 2001, attacks, according to counterterrorism experts. U.S. authorities have linked the Islamic State to dozens of plots of attacks against the West, including at least nine inside the United States since January.

The torrent of terror activity includes a sharp rise in extremism within the United States, as terrorists overseas and here at home seek to radicalize and recruit operatives across America's diverse communities. This year alone, the FBI has arrested more than 60 U.S.-based Islamic State supporters, and FBI Director James Comey recently said the agency is investigating homegrown violent extremists in every state.

According to McCaul, last year saw the highest number of global terrorism incidents on record, with attacks rising 35 percent over the previous year and terror deaths worldwide nearly doubling. Officials now estimate that more than 250 Americans have sought to join or succeeded in joining extremists groups in Syria.

Americans are increasingly concerned that "we are losing on the home front" where Islamic State supporters are starting to permeate our society with alarming speed, McCaul said.

There are terrorist sympathizers operating within communities across the country, intent on striking from within. U.S. authorities say they are aware of at least a dozen Islamic State-linked terrorist plots within the United States, including recently thwarted plans to set off pipe bombs on Capitol Hill, behead law enforcement officers, conduct mass shootings, detonate bombs near U.S. lawmakers and livestream a murderous rampage at a college campus.

A majority of these domestic Islamic State supporters never set foot overseas, but instead were recruited over the Internet and given the group's online propaganda.

"And with over 200,000 ISIS tweets per day — an astounding number — how could we possibly get a handle on this?" McCaul said. "The chatter is so high and the volume is so loud … this isn't terror as usual. This is terror gone viral."

While federal and local law enforcement should be commended for disrupting so many plots, Chattanooga is a grim reminder than authorities can't stop all of them.

McCaul believes there is far more the federal government should and can do to curb the threat. He has started a working group between federal homeland security agencies and the high-tech community to start a national dialogue about what the country can do to stop terrorist hijacking of social media and other Silicon Valley technology for terrorist recruiting and plots.

In mid-July, McCaul's committee unanimously approved a bill aimed at making domestic extremism a top priority within the Homeland Security Department, including creating a new office dedicated to preventing Americans from being radicalized and recruited by extremist groups.

The measure establishes the Office for Countering Violent Extremism, or CVE within DHS, providing $10 million annually to ramp up the department's efforts. While it doesn't mention Islamic-extremism by name, part of the CVE's new mission would be identifying "risk factors" for extremism and "identifying populations targeted by violent extremist propaganda, messaging or recruitment."

But the bill has attracted a fair amount of opposition from civil liberties groups that worry it will lead to more targeting of Muslim-Americans and inappropriately use community outreach programs to gather intelligence on groups and individuals.

"We believe that this effort is unnecessary, it would be a waste of taxpayer funds and it threatens to entrench a program that raises civil liberties and privacy concerns," Hina Shamsi, director of the national security project at the American Civil Liberties Union, told the International Business Times after the bill passed the Homeland Security panel.

But McCaul and those supporting the bill argue that many minority and Muslim communities across the country don't want to see their young men and women radicalized online or otherwise, and are eager to work with authorities to prevent it from happening.

Supporters point to red flags from terrorists like the Tsarnaev brothers, who carried out the attack on the Boston Marathon. They say authorities are missing those kinds of threats because they aren't reaching out to Muslim communities.

Tamerlan Tsarnaev, the elder brother, was thrown out of his Cambridge, Mass., mosque for yelling at his imam just three months before carrying out the marathon bombing.

"It would have been nice to have known that," McCaul said.