Bipartisan Alarm: Another 9/11 May Be Imminent

As the world watches the Islamic State (ISIS) army carry out atrocities in Iraq, many lawmakers are concerned Americans could soon wake up to another 9/11.

At least 100 Americans are believed to be fighting with ISIS, some of whom will eventually return to U.S. soil.

The news comes amid new concerns about the Department of Homeland Security's ability to track potential threats in the United States.

Authorities say as many as 6,000 foreign nationals who arrived in the country on student visas have vanished.

"They just disappear," Sen. Tom Coburn, R-Okla., who sits on the Homeland Security Oversight Committee, said.

They're taking advantage of a program offered at Harvard, Yale, and other major institutions. It's how one of the 9/11 hijackers got into the country before flying a jet into the Pentagon.

Islam: Religion of Peace or War?
Arabic scholars bring you a historical and shocking narrative on the tenets of Islam and the life of its founder.
Know the truth. Download now.

And an ABC News investigation found that the visa loophole still has not been fixed.

"It's been pointed out over and over again and the fact that nothing has been done about it yet is very dangerous for all of us," Tom Kean, former co-chair of the 9/11 Commission, said.

The news comes after warnings from the king of Saudi Arabia that Islamic State terrorists are likely to attack Europe and the United States before the end of the year if there is not a strong international response soon.

On Tuesday, Britain's prime minister unveiled a new package of legislation aimed at preventing attacks in the United Kingdom by Islamic jihadists returning from the Middle East.

"We have already taken a wide range of measures, including stopping suspects from travelling to the region by seizing passports, barring foreign nationals from re-entering the United Kingdom," Prime Minister David Cameron said.

While Cameron has a plan, President Barack Obama is taking heat from both Republicans and Democrats for admitting he doesn't yet have a strategy for dealing with the growing threat posed by the Islamic State.

Sen. Diane Feinstein, the top Democrat on the Senate Intelligence Committee, said she knows the president is very cautious, but in this case he may be "too cautious."

"This is really the first group that has the wherewithal in terms of financing, the fighting machine in terms of a structure -- heavy equipment, heavy explosives, the ability to move quickly. This is a group of people who are extraordinarily dangerous. And they'll kill with abandon," the California lawmaker told NBC's "Meet the Press."

Republicans are taking a much stronger tone.

"I think it starts with an understanding that this is a direct threat to the United States of America, that it may be one of the biggest we have ever faced," Sen. John McCain, R-Ariz., told CBS's "Face the Nation."

"I was astounded when the president of the United States said that the world has always been messy and it has been accentuated by social media. That means that the president of the United States is either in denial or overwhelmed," he charged.

The president's response came as no surprise to Rep. Mike Rogers, R-Mich.

"Well, unfortunately, we find it consistent with his past policy and actions on foreign policy. And it shows -- I think exemplifies his foreign policy is in absolute free fall," Rogers told "Fox News Sunday."

Rogers also criticized the president's foreign policy in dealing with Russia, Iran, and North Korea. He said America's allies no longer trust the United States to lead the world through difficult times.