The analysts from the Center for Strategic and Budgetary Assessments were speaking at the National Press Club on lessons learned 10 years after the 2001 terrorist attacks.
The defense budget over the next decade could decline by 31 percent, said senior fellow Todd Harrison, assuming enactment of all cuts proposed by President Obama as well as decreases that could be automatically triggered under the recently enacted Budget Control Act. That drawdown, he said compares with cuts of 53 percent after the Korean War, 26 percent after the Vietnam War and 34 percent after the end of the Cold War.
What makes the current defense budget situation unusual, Harrison said, is that the past decade's average defense spending hike of $300 billion a year "was not really a buildup" in that much of it went to the wars in Afghanistan and Iraq and increases in salaries, health care and benefits for military personnel.
"9/11 obscured the need to prioritize at the Pentagon," he said, "and it's not realistic to continue to do what we do today. But the moment now provides a fiscal imperative to make choices on countering future threats."
Rather than making across-the-board cuts that are "fair and balanced," he said, the cuts should be strategically targeted. "But given the current uncertainty, the best the Pentagon can do is come up with a list of options," he added.
Center President Andrew Krepinevich said the Defense Department "must identify not just what we will accomplish but what we will not do as well." He advised against telling Congress' newly convened budgetary "supercommittee" something as simple as, "Don't cut defense because we need a strong defense." Instead he recommended a "coherent approach" that minimizes surprises and factors in risks, costs, priorities and strategies by looking for "areas of enduring advantage aligned with our competitors' enduring weaknesses."
Krepinevich described the changing threats in the post-9/11 world, the Arab spring, the economic surge of China and Brazil, small missiles used by irregular warfighters, nuclear proliferation in the developing world, and dramatic changes in demographics and technology. Those realities call for new defense approaches in multiple domains -- land, air, sea, and cyberspace, he said. "The challenge is growing it at same time that resources diminishing, unusual circumstances that mirror the 1930s," he said.
Giving a historical perspective, Jim Thomas, the center's vice president and director of studies, said, "The American response to 9/11 involved more of continuity than a departure, though it was a watershed event at DoD." Elements of the modern threat -- non-state adversaries, irregular warfare, a non-linear battlefield, and less-than-clear definitions of victory -- go back to America's experience with the Indian Wars, the Barbary pirates and the War of 1812, he said.
But the Pentagon "had been lulled into a false sense of security after the end of the Cold War" and forgot some of the lessons of Vietnam after the relatively easy success of the first Iraq war and the invasion of Iraq in 2003.
"The 9/11 era is drawing to a close, and it's time to plan for the post 9/11era," Harris said. The new era "will surpass Cold-war in terms of global posturing," he added, "and there is a blurred distinction between our vital and our peripheral geographical interests. The 21st century enemy is unlikely to fight the way we would prefer."