During a two-hour briefing Friday, Pentagon officials fielded questions from roughly 40 staffers, but provided scant details -- even during a short classified session -- on the precise number and types of platforms it needs for future missions.
More detailed explanations will be outlined in the complete classified report, expected on Capitol Hill by the end of next month.
Lawmakers hoped to receive the study earlier this year, long before the congressional defense committees marked up their annual authorization and spending bills.
But with the late release, it is unclear what, if any, influence the mobility study will have on the fiscal 2006 budget. Congress will, however, use it to evaluate President Bush's fiscal 2007 Pentagon budget request, due in February, a congressional source familiar with the study said Monday.
Pentagon briefers, led by an Army colonel, told congressional staffers that the Pentagon's current plans for cargo aircraft and ships will be adequate to combat future threats and provide assistance for major humanitarian operations around the world.
"They're in pretty good shape given what they're willing to risk," the source said.
However, the Pentagon based its review on current budget projections through 2011, which officials now are reworking to reflect growing pressure among all federal agencies to slash funding.
The Defense Department might outline its own list of recommended budget cuts as early as late November, defense sources have said. The cuts will strike across the services, with budget reductions expected for some of the military's priciest and most ambitious programs.
The lengthy mobility report will detail several what-if scenarios, as well as the risks the military will incur if the anticipated size and makeup of its air and sea fleet changes over time, congressional sources said.
"There's an awful lot of wiggle room in this study right now," another congressional source said.
The study also will help Congress and the Pentagon determine how to proceed with plans to modernize the Air Force's aging fleet of KC-135 aerial refueling tankers.
A three-year investigation led by Senate Armed Services Airland Subcommittee Chairman John McCain, R-Ariz., thwarted Air Force efforts to lease a fleet of 100 tankers from Boeing. That investigation has led to the resignation of Air Force leaders and the incarceration of two senior Boeing executives.
The Pentagon officials stressed that they conducted the mobility review in conjunction with an ongoing "analysis of alternatives" studying Air Force tanker options, sources said. That review, which also has been delayed several months, is due to Congress in November.
Democrats and Republicans alike have been growing increasingly frustrated in recent months over the delay in the report's release.
During a Senate Armed Services Committee confirmation hearing in July, Armed Services ranking member Carl Levin, D-Mich., and Sen. James Inhofe, R-Okla., both pressed top military leaders on the intended completion date for the study.
"It is critical to get that done," Inhofe said, noting that the Pentagon told Congress in April the study would be completed shortly. "Well, shortly's come and gone."