The Air Force is creating a new command to manage the nation's nuclear arsenal better after a series of embarrassing missteps in the handling and oversight of its most sensitive materials.

Air Force Secretary Michael Donley told reporters Friday that the service is shifting its nuclear-capable bombers, missiles and staff into a new Global Strike Command. So far officials have spent more than $200 million on the reorganization effort, and expect to spend another $270 million during the budget year that began Oct. 1. Air Force leaders could not provide a total cost or staffing for the new command, which will be led by a lieutenant general, the force's second-highest rank.

Donley said the latest shuffle would be a "new starting point" that would reinvigorate the service's nuclear mission. He also said it would help the Air Force focus on the arsenal's management, no matter how small it might become under future international agreements.

The idea for a new, separate command stemmed from a recent highly critical report that concluded there has been a decline in the Air Force's focus on its nuclear mission, the performance of those who carry it out the failure of its leaders to respond effectively.

Planned changes involve improved inspections, more emphasis on nuclear expertise and a better coordinated system to track nuclear materials. Control of the B-2 and B-52 bombers now under Air Combat Command, and the intercontinental ballistic missiles now under Space Command will shift to the newly formed Global Strike Command.

While largely bureaucratic in nature, the changes reflect a realization by the Air Force that in the post-Cold War era, attention to the nuclear mission had slipped and must now be corrected. It took a series of embarrassing incidents that eventually prompted Defense Secretary Robert Gates to fire the previous Air Force secretary and chief of staff.

The two major blunders involved the mistaken shipment to Taiwan of four electrical fuses for ballistic missile warheads and the flight of an Air Force B-52 bomber, mistakenly armed with six nuclear-tipped cruise missiles, from an Air Force base near the Canadian border across several states to land at a base near the Gulf of Mexico. At the time, the pilot and crew were unaware they carried nuclear arms.

A Pentagon advisory group, in a review of the problems, recommended last month that nuclear responsibilities be coordinated under the already existing Space Command, which is responsible for the service's land-based nuclear missiles but not other nuclear weapons.

Asked why officials chose to create a new command rather than follow the group's recommendation, the Air Force Chief of Staff, Gen. Norton Schwartz, said officials believed that lumping all the responsibility for space, cyber and nuclear issues would be too much for one command.