WASHINGTON, Nov. 2, 2011 -- Damage to the Army, Navy, Air Force and Marine Corps could be irreversible if the Budget Control Act's "sequestration" provision takes another $600 billion from the defense budget, the military service chiefs said today.Army Chief of Staff Gen. Raymond T. Odierno, Chief of Naval Operations Adm. Jonathan W. Greenert, Air Force Chief of Staff Gen. Norton A. Schwartz and Marine Corps Commandant Gen. James F. Amos testified before the House Armed Services Committee here on the future of the military services.A bipartisan congressional committee is working to identify $1.5 trillion in federal budget savings and to make a recommendation to Congress by Nov. 23. If Congress fails to act on the committee's recommendation by Dec. 23, the sequestration mechanism would kick in.Odierno said he shares concerns expressed by Defense Secretary Leon E. Panetta and other military officials about the harmful effects of sequestration, which would mean a total Defense Department budget reduction of more than $1 trillion over 10 years."Cuts of this magnitude would be catastrophic to the military," Odierno told the House members. "In the case of the Army, it would significantly reduce our capability and capacity to assure our partners abroad, respond to crisis and deter our adversaries while threatening the readiness and potentially the all-volunteer force."Sequestration would significantly reduce active and reserve component strength, impact the industrial base and nearly eliminate Army modernization programs, Odierno said."It would require us to completely revamp our national security strategy and reassess our ability to shape the global environment in order to protect the United States," the general said."With sequestration," he added, "my assessment is that the nation would incur an unacceptable level of strategic and operational risk."In the Navy's view, sequestration would cause "irreversible damage," Greenert said."It will hollow the military, and we will be out of balance in manpower, both military and civilian, procurement and modernization, he said, adding that the subsequent effect on the industrial base "might be irrecoverable."Likening the Marine Corps to an affordable insurance policy, Amos said that at less than 7.8 percent of the total DOD budget, the Marine Corps and its Navy-counterpart amphibious forces "represent a very efficient and effective hedge against the nation's most likely risks."While the nation works to reset its military forces with the last U.S. forces scheduled to leave Iraq shortly and a drawdown under way in Afghanistan, "it does so in increasingly complex times, as we explore ways across the department to adjust to a new period of fiscal austerity," he said.The clear imperative, Amos added, is that the United States "retains a credible means of mitigating risk while we draw down the capacity and the capabilities of our nation."For the Air Force, Schwartz said sweeping defense cuts mandated by the sequestration provision would gravely undermine the nation's ability to protect itself."At a minimum, [such cuts] would slash all our investment accounts, including our top-priority modernization programs such as the KC-46 tanker, the F-35 joint strike fighter, the MQ-9 remotely piloted aircraft and the future long-range strike bomber," he added."It would raid our operations and maintenance accounts, forcing the curtailment of important daily operations and sustainment efforts," Schwartz said, adding that second- and third-order effects, some now unforeseen, "will surely diminish the effectiveness and well-being of our airmen and their families."The ongoing DOD budget review shows that further spending reductions "cannot be done without substantially altering our core military capabilities, and therefore, our national security," the general said.Another Air Force capability that would succumb to sequestration cuts is that of executing concurrent missions across the spectrum of operations around the globe, he added."For example, the Air Force's simultaneous response to crisis situations in Japan and Libya, all the while sustaining our efforts in Afghanistan and Iraq, will be substantially less likely to happen in the future, from humanitarian relief in East Asia to combat and related support in North Africa," Schwartz said."In short, your Air Force will be superbly capable and unrivaled, bar none, in its ability to provide wide-ranging game-changing air power for the nation," the general said, "but as a matter of simple physical limitations, it will be able to accomplish fewer tasks in fewer places in any given period of time."At the Pentagon today, Press Secretary George Little characterized for reporters what sequestration-prompted defense cuts could mean for the services."The reality is that we've done the analysis, and we would face the smallest Army and Marine Corps in decades, the smallest Air Force in the history of the service, [and] the smallest Navy since the Woodrow Wilson administration if sequestration were to happen," he said.Such cuts would have a severe impact on jobs inside the Defense Department and for the defense industrial base, he said, adding that skills and expertise in the defense industrial base create new capabilities for the U.S. military going forward."The threats aren't going away, and we need to be prepared," he added.Hollowing out the force and the defense industrial base "would create significant problems for our national security," Little said.