Osama bin Laden's spokesman and son-in-law is in U.S. custody. American leaders are calling Sulaiman Abu Ghaith's capture a "very significant victory" in the ongoing fight against al Qaeda.

Abu Ghaith became an international name in late 2001 when he appeared on satellite television urging Muslims everywhere to fight the United States and warning of more attacks similar to those of 9/11.

Rep. Peter King, the former chairman of the House Homeland Security Committee, credited the CIA and FBI with capturing Abu Ghaith in Jordan within the last week.

"Definitely, one by one, we are getting the top echelons of al Qaeda," King, R-N.Y., said. "I give the [Obama] administration credit for this: it's steady and it's unrelenting and it's very successful."

King also confirmed Abu Ghaith was involved in the planning of the 9/11 attacks against the World Trade Center and Pentagon.
 
Tom Lynch, a research fellow at the National Defense University in Washington, described Abu Ghaith as a member of al Qaeda's core leadership.

He's "capable of getting the old band back together and postured for a round of real serious international terror," Lynch said.
 
"His capture and extradition not only allows the U.S. to hold -- and perhaps try -- a reputed al Qaeda core survivor, further tarnishing the AQ core brand, but it also points to the dangers for those few remaining al Qaeda core refugees," Lynch said.

Law enforcement sources say Abu Ghaith will be brought to the United States and prosecuted in a New York federal court on terror charges.