Horrific terrorist carnage in Paris has refocused Washington's attention on the Islamic State (IS) group and its ambition to strike within the United States.
Amid a global outpouring of grief and sympathy for France, are reminder the top Democrat on the House Intelligence Committee,that America is also a target.
"We cannot allow ISIS to have this sanctuary in Syria and Iraq from which to plan and direct attacks against us," Schiff added.
White House officials are seeking to reassure the American public.
"There is not a specific, credible threat to the homeland at this time, but we are going to be very vigilant," said President Barack Obama's deputy national security adviser, Ben Rhodes, also on This Week.
Of particular concern: the Paris attacks demonstrated that terrorists can plan, coordinate and execute bloody plots with little or no Internet chatter or other communication that may tip off intelligence agencies. If Islamic State caught France by surprise, could it do the same to the United States?
"The reality is: even the best intelligence will not stop a determined enemy that adapts to our defenses, and ISIS has adapted," said Schiff.
Refugee dilemma
Reports that one of the Paris attackers may have been a Syrian asylum seeker will bring increased scrutiny of the Obama administration's pledge to accept 10,000 refugees from Syria.
For months, Republican presidential contenders have blasted the administration's campaign against IS as woefully inadequate. Now, they are disputing White House assurances that Syrians granted U.S. asylum will be subjected to thorough screening and vetting.
"You have a thousand people come in, and 999 are just poor people fleeing oppression and violence. But one of them is an ISIS fighter. If that is the case, then you have a problem, and there is no way to vet that out," said Republican Senator Marco Rubio. "You cannot pick up the phone and call Syria."
At Saturday's debate among Democratic presidential hopefuls, Hillary Clinton pointedly disagreed with Obama's assertion last week that the Islamic State group has been contained.
White House officials say the president was referring to the territory controlled by IS in Iraq and Syria, not the terrorist threat posed by the group.
Vocabulary
sanctuary:(圣经)圣幕,圣堂
vigilant:警惕的
asylum:庇护;收容所
assertion:断言,声明
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