WASHINGTON (CBS News) - Millions of people turned out in France over the weekend to march in solidarity after a week of fear and carnage. But as the world tries to move on from the horror of the past week's terrorist attacks, one question still lingers: How do we prevent this from happening again?
Attorney General Eric Holder traveled to Paris over the weekend to meet with foreign leaders to tackle that question. He also announced a summit on extremism to be held next month in Washington
Appearing on "Face The Nation" on Sunday, Holder said the Obama administration would work closely with its allies to prevent future attacks by Western-born jihadists who are increasingly traveling to places like Syria and Yemen to train with terrorist groups. He also spoke about the threat of so-called "homegrown extremists" who can be radicalized here in the U.S. by things they see on the Internet.
"It's something that frankly keeps me up at night," Holder said. "Worrying about the lone wolf or a group of people, a very small group of people, who decide to get arms on their own and do what we saw in France this week. It's the kind of thing that our government is focused on doing all that we can, in conjunction with our state and local counterparts to try to make sure that it does not happen."
He also said that investigation into whether former CIA Director David Petraeus disclosed classified information to his mistress was being handled by the "highest levels" at the Justice Department.
His comments were covered by the Associated Press, Reuters, The New York Times, The Wall Street Journal, the Washington Post, the Los Angeles Times, USA Today, National Review, The Hill, the International Business Times, BuzzFeed News, the Washington Free Beacon.
On the issue of threats to the homeland, NYPD Deputy Commissioner John Miller told "Face The Nation" host Bob Schieffer that the department was reviewing a new ISIS video that called on Muslims to attack police in their home countries. His comments were covered by CNN and the Washington Times.
Two top Republicans said Sunday on "Face The Nation" that President Obama and his European counterparts need to take a tougher stand on terrorism in the face of new, complex threats.
"We had the woman, the female terrorist, leave and go to Syria -- but she's on a no-fly list," said Rep. Michael McCaul, the Texas Republican who chairs the House Homeland Security Committee. "Europe has to strengthen and tighten its travel restrictions, but we need to look at protecting this country because I see it as a real threat."
Sen. John Cornyn, R-Texas, the second most powerful Senate Republican, said President Obama has a "tendency toward political correctness" and doesn't even use tough talk when it comes to terrorism.
"And they are calling the war on terror 'overseas contingency operations,'" Cornyn said. "We need to call it what it is. Because that's the first step to actually dealing with it on a realistic basis."
Turning to domestic issues, Congress is expected to authorize construction of the Keystone Pipeline this week. President Obama has threatened to veto the bill, and Cornyn admitted Sunday that the Senate probably can't override it.