CBS News homeland security correspondent Bob Orr says U.S. officials are openly nervous about a possible attack between now and the new year - the primary fear being that terrorists could once again try to smuggle explosives aboard airplanes.
With Christmas just a day away, the Transportation Security Administration is stepping up its hunt for bombs, ordering its officers to check insulated drink containers for hidden explosives.
Sources say there is no intelligence suggesting an imminent plot involving thermos bombs, but a statement on the TSA website warns: "The possible tactics terrorists might use include the concealment of explosives inside insulated beverage containers."
"Finding innovative ways to smuggle explosives onto aircraft has always been a favorite topic of discussion among members of the online jihadi community," notes CBS News' Khaled Wassef, who monitors the web traffic of extremist groups and jihadist chat rooms closely.
"There are several tutorials available on the web, explaining how to smuggle explosives onboard aircraft by concealing them inside Coke cans, packs of cigarettes, cameras, and medication packaging," explains Wassef. "These tutorials also discuss the various explosives detection systems in use at airports, and ways to bypass them."
Orr notes that 2010 has already been a year of foiled plots and close calls.
Persistent threats on jihadi websites make it clear terrorists are plotting more strikes.
"We're going to do our best to disrupt these plots and their plans before they ever make it to the homeland," White House counterterrorism advisor John Brennan tells CBS News.
Al Qaeda has not historically targeted Western holidays, but that seemed to change a year ago when Umar Farouk Abdulmutallab smuggled an underwear bomb aboard Northwest Airlines flight 253 on Christmas Day.
That attack was carried out by al Qaeda in the Arabian Peninsula, the same Yemen-based group behind this fall's cargo plot. One of the key figures at the center of AQAP is Fort Hood gunman., the same American born cleric who inspired the
Now intelligence analysts worry Awlaki's charismatic message could move more homegrown radicals in the U.S. to take action in al Qaeda's name.
Former CIA analyst Phil Mudd says al Qaeda, "never intended to conduct every attack themselves. They intended to spark a wave of people worldwide who would do it for them."
Officials say U.S. defenses have been bolstered at airports, and even train stations, and relentless drone strikes in Pakistan have weakened Osama bin Laden's core group. But the danger has not been eliminated.
"We need to be on top of our game, particularly during the holiday season, but throughout the year," advises Brennan.
Officials say they've improved information sharing, and our readiness is better than it was a year ago. The problem is, the threat has also gone up.