With sequestration cemented as law into the foreseeable future, the Air Force's top officer today discussed some tough choices the service faces as its leaders try to pare $12 billion from the budget.

In the final session of the Joint Chiefs of Staff series at the American Enterprise Institute here, Air Force Chief of Staff Gen. Mark A. Welsh III outlined the Air Force's core missions with a focus on balancing capability, capacity and readiness.

The Air Force is entangled in a "ready today" versus "modern tomorrow" challenge, Welsh said, while delivering air and space superiority, intelligence, surveillance and reconnaissance, rapid global mobility, global strike and command and control.

"These five missions haven't changed at all," the general said. "This is still the core of what we are expected to provide our combatant commanders worldwide, ... (but) the way we've done it has changed pretty dramatically in some areas over the years."

Air superiority, Welsh said, allows ground and maritime forces freedom to attack and freedom from attack.

"Since the Korean War, this nation has deployed about 7 million men and women at arms to different contingencies around the world," Welsh said. "None of them have died as the result of enemy air attack -- that doesn't happen by accident."

Space superiority, while relatively new to the mission set, continues to grow in importance, with the Air Force controlling more than 170 satellites of the nearly 2,200 flying today in space.

"Our Air Force's job is to monitor that [and] to provide missile warning ... secure communication, secure and precise navigation and precise timing," Welsh said. "We have about 26,000 Airmen who do that every single day."

Whether managed by space forces or with airborne platforms, intelligence, surveillance and reconnaissance remains as an integral part of the mission, the general said. In 2006, the Air Force completed its goal -- a $55 billion effort -- to field 21 orbits of full-motion video MQ-1B Predator unmanned aerial vehicles.

"Since then, we've added about 42 more orbits, and we're on our way to 65 total," Welsh said.

The Air Force chief of staff emphasized that his service is charged to support the combatant commander and the joint task force commander with an operational ISR capability.

"We have to figure out how to take what we now have, get rid of some of it, and reinvest it into what they really need for the future," he said.

Mobility, Welsh said, is another large enterprise for the Air Force, with about 132,000 active, Guard and Reserve Airmen conducting the mission daily and with a strategic airlift sortie launch every two minutes of every hour, every day of the year.

"As we talk about whether to move a ground unit or humanitarian assistance to any part of the world, the one question that is never asked is 'Can we get it there?'" Welsh noted.

For everything from close-air support to nuclear strikes, some 40,000 Airmen work the nuclear deterrence mission around the clock for the Air Force's global strike capability. The general referred to a recent photo depicting successful strikes in Libya.

"One airplane, one pass, 16 independently-targeted, joint-directed (tactical) munitions against an airfield in Libya," Welsh said. "We're phenomenally good at what we do."

Commanders, with the help of about 53,000 Airmen each day, rely on command and control, whether for missile defense, air operations or humanitarian support, Welsh said.

"(It's) high technology, lots of people, and there's nothing easy about this work," the general said. "It drives every other part of the activity that goes on in the theater."

The Air Force differs from other services, specifically by providing support for ongoing operations from home stations, Welsh said.

"About 220,000 ... of the people in our Air Force today are engaged in supporting combatant commander operations all over the world," he said. "There's only 27,000 actually deployed, and ... 56,000 actually stationed overseas. ... The rest are all supporting 24/7 operations for home station."

Because this non-stop, global support requires money, training and a dedicated force of people who can perform their jobs on a large scale, Welsh said, the Joint Chiefs of Staff met at the White House to discuss ideas, concerns and a budget strategy with President Barack Obama, the White House chief of staff and national security advisers.

Welsh said he got "a pretty good feeling" that the president understands the issues.

"He was engaged in the conversation, he was knowledgeable about the issues, (and) he asked a lot of questions. ... Most importantly, he listened to the answers. He paid attention," Welsh said.

And now the service chiefs find themselves in the surreal position of figuring out the way ahead to meet the requirements of the law.

"Sequestration is the law, and it's time to start thinking about what that means to us," Welsh said. "You can't continue to defend everything and pay a $1.3 billion bill."

But life under sequestration requires a self-analysis and a well-defined objective, Welsh said.

"The assumption we are using is that you have an Air Force to fight and win the full-spectrum, high-end fight," Welsh said. "If you lose the counterinsurgency action, it'll be embarrassing. If you lose the full-spectrum conflict, it could be catastrophic -- that's why you build an Air Force."

With a significant portion of the budget earmarked for space, intelligence, installations, civilian pay, military pay and force structure, the challenge of where to cut persists, the general said.

"The reality of sequestration," he said, "is that even if we can adjust the cost of people ... and installations and get rid of those things we think are excess, that may be 1 percent of our overall budget. ... But it's not going to pay the $12 billion a year we owe for sequestration."

Welsh put the figure into perspective in terms of flying hours and electricity.

"We'd have to stop flying every airplane in the Air Force for two years ... to get $12 billion," he said. "We'd have to turn off the lights and utilities at every installation in our Air Force ... for 12 years to get that kind of savings."

He added that people who think they'll find the savings by decreasing temporary duty assignment accounts, cutting conferences or by decreasing bloated staffs "aren't living in the reality of today." Future budgets, the general underscored, will require cuts from readiness, force structure and modernization, not people or facilities.

"That's where the money is, that's where your savings have to be," he said. "Do we want a ready-for-today (force) or a modern force tomorrow? You can't have both."

Welsh said the Air Force is looking at cutting up to 50 percent of its modernization programs.

"There are three major programs, the F-35 (Lightning II), KC-46 and long-range bomber that we think are critical to being a viable, credible Air Force in the future," he said. "Because we're a platform-based force, we have to invest now to have those things by (the mid-2020s)."

To avoid cuts to vital training and other programs, the Air Force may face fleet divestitures until the budget is finalized, Welsh said.

"You don't save billions of dollars by nibbling around the edges of things -–- you can't get there from here," he said.