A nearly two-month lull in American drone strikes in Pakistan has helped embolden al Qaeda and several Pakistani militant factions to regroup, increase attacks against Pakistani security forces and threaten intensified strikes against allied forces in Afghanistan, American and Pakistani officials say.
The insurgents are increasingly taking advantage of tensions raised by an American airstrike in November that killed two dozen Pakistani soldiers in two border outposts, plunging relations between the countries to new depths.
The Central Intelligence Agency, hoping to avoid making matters worse while Pakistan completes a wide-ranging review of its security relationship with the United States, has not conducted a drone strike since mid-November.
Diplomats and intelligence analysts say the pause in CIA missile strikes - the longest in Pakistan in more than three years - is offering for now greater freedom of movement to an insurgency that had been splintered by in-fighting and battered by American drone attacks in recent months.
Several feuding factions said last week that they were patching up their differences, at least temporarily, to improve their image after a series of kidnappings and, by some accounts, to focus on fighting Americans in Afghanistan.
Other militant groups continue attacking Pakistani forces. Just last week, Taliban insurgents killed 15 security soldiers who had been kidnapped in retaliation for the death of a militant commander.
The spike in violence in the tribal areas - up nearly 10 percent in 2011 from the previous year, according to a new independent report - comes amid reports of negotiations between Pakistan's government and some local Taliban factions, although the military denies that such talks are taking place.
A logistics operative with the Haqqani terrorist group, which uses sanctuaries in Pakistan to carry out attacks on allied troops in Afghanistan, said militants could still hear drones flying surveillance missions, day and night.
"There are still drones, but there is no fear anymore," he said. The logistics operative said fighters now felt safer to roam more freely. Over all, drone strikes in Pakistan dropped to 64 last year, compared with 117 strikes in 2010, according to The Long War Journal.