Federal authorities on Friday arrested a 29-year-old Moroccan man in an alleged plot to carry out a suicide bombing at the U.S. Capitol, the latest in a series of terrorism-related arrests resulting from undercover sting operations.

For more than a year, Amine El Khalifi, of Alexandria, considered attacking targets including a synagogue, an Alexandria building with military offices and a Washington restaurant frequented by military officials, authorities said. When arrested a few blocks from the Capitol around lunchtime on Friday, he was carrying what he believed to be a loaded automatic weapon and a suicide vest ready for detonation.

The gun and vest were provided not by al-Qaeda, as Khalifi had been told, but by undercover FBI agents who rendered them inoperable, authorities said.

They said Khalifi had been the subject of a lengthy investigation and never posed a threat to the public. On Friday afternoon, he made an initial court appearance in U.S. District Court in Alexandria, where he was charged with attempting to use a weapon of mass destruction against federal property. He faces life in prison if convicted.

These stings always raise the question - as they should; if the FBI wasn't involved, would the guy have gone through with it?

Ashraf Nubani, a Muslim lawyer in Washington who has defended terrorism suspects in similar cases in the past, said he has has watched with alarm the increase of such FBI stings.

"It's controlled from beginning to end by FBI. But you can't create a terrorism case and then say you stopped it," Nubani said. "Had the FBI not been involved, through their manipulation or informants, would the same thing have happened? Would there be attempted violence? They have their sights on certain people, the ones who talk big talk."

Dean Boyd, a spokesman for the Justice Department, said the affidavit in the Khalifi case makes clear that "at each step, it was the defendant who proposed the alleged plot and sought help in obtaining the weapons to carry it out."

"Whenever we conduct an undercover operation of this sort, we fully anticipate that allegations of entrapment will be raised as a defense, and we conduct the investigation accordingly to assure that entrapment does not occur," he said.

It's a fine line, but I think the FBI walked it successfully this time. Of course, we don't have all the details, but it appears that the would-be terrorist was fully committed by his own planning to carry out a mass terror attack.

And as far as the "ones who talk the big talk," that Muslim lawyer has to know that ignoring the stated intent of these people is done at the peril of being proved wrong and experiencing a horrifying attack. The FBI has a responsibility to protect us. If that means seeking out potential terrorists and keeping tabs on them by facilitating their plot, as long as they follow the law there should be no problem in taking them down.