LANGLEY AIR FORCE BASE, Va. – The Pentagon for the first time is considering scaling back the massive buildup of drones it has overseen in the past few years, both to save money and to adapt to changing security threats and an increased focus on Asia as the Afghanistan war winds down.

Air Force leaders are saying the military may already have enough unmanned aircraft systems to wage the wars of the future. And the Pentagon’s shift to Asia will require a new mix of drones and other aircraft because countries in that region are better able to detect unmanned versions and shoot them down.

If the Pentagon does slow the huge building and deployment program, which was ordered several years ago by then-Defense Secretary Robert Gates, it won’t affect the CIA drone strikes in Pakistan, Yemen and elsewhere against terror suspects.

Those strikes were brought center stage last week during the confirmation hearing for White House counterterror chief John Brennan, President Obama’s pick to lead the CIA.

Gen. Mike Hostage, commander of Air Combat Command, said senior leaders are analyzing the military’s drone needs and discussions are beginning. But he said the current number patrolling the skies overseas may already be more than the service can afford to maintain.

Overall, Pentagon spending on unmanned aircraft has jumped from $284 million in 2000 to nearly $4 billion in the past fiscal year, while the number of drones owned by the Pentagon has rocketed from fewer than 200 in 2002 to at least 7,500 now. The bulk of those drones are small, shoulder-launched Ravens owned by the Army.

The discussions may trigger heated debate because drones have become so important to the military. They can provide 24-hour patrols over hotspots, gather intelligence by pulling in millions of terabytes of data and hours of video feeds, and they can also launch precisely targeted airstrikes without putting a U.S. pilot at risk.