Editor's note: Michael O'Hanlon, senior fellow at the 21st Century Defense Initiative at Brookings, is co-author with Hassina Sherjan of the new book "Toughing It Out in Afghanistan."
(CNN) -- The newly released Pentagon strategy paper, known as the Quadrennial Defense Review, is a solid document, but also one that reminds us of the limits of such planning papers at this point in American security policy.
The document does what any responsible American defense planning document would have to do at this point in history -- spreading relatively abundant, but still quite finite, resources across a wide range of current and hypothetical missions.
The United States has some 70 allies toward whom it has made formal defense commitments, necessitating significant levels of military preparation from East Asia to the Middle East to this hemisphere.
It has major serious core interests ranging from stemming nuclear proliferation to contending with the spread of advanced missiles and other dangerous technologies to preserving a stable international order consistent with global economic prosperity to deterring the rise of hostile new powers.
It is still fighting two wars while casting a wary eye, and devoting limited resources, to lesser roles in other conflicts in the broader Middle East region. It has to worry about homeland security and fighting terrorism, hemispheric missions like disaster response (as in Haiti) and counter-narcotics operations as well.
The Afghanistan mission is an important place to begin the discussion. This year and next, the United States will deploy up to 100,000 troops in that country for much if not most of the year. Not only does that translate into $100 billion a year in added defense costs, above and beyond those of simply maintaining the military, but it also requires a standing ground force of a given size in order to handle such burdens over time.
As Hassina Sherjan and I argue in a new book, "Toughing It Out in Afghanistan," we should know a lot later this year and certainly by 2011 about whether our basic strategy is working there, but it may not be until 2012 or 2013 when U.S. force levels return back to 50,000 or fewer. Not only that, but the United States still has 100,000 troops in Iraq and will perhaps still have 40,000 there at the end of 2010.
Those are the wars we are actively fighting. But there are also those we are trying to deter against. Take two contingencies in East Asia. The chances of another Korean war seem very small, but part of the reason is the degree of commitment of American forces to the theater.
While South Korean armed forces are much better than ever, North Korean leaders might still be tempted to provide a confrontation -- or at least walk right up to the brink of one -- absent a sustained American commitment that makes the ultimate outcome of any war beyond any doubt to anyone.
And even more foreboding (and perhaps somewhat more likely) is a war between China and Taiwan that ultimately drags in the United States. Again, on a normal day everyone in this equation would seem to have ample reasons not to fight. But many in Taiwan still want their independence, virtually no one in China would tolerate or condone such a development, and American planners feel historic as well as strategic reasons to be sure that Taiwan is not forsaken. This war cannot be totally dismissed as a possibility -- which means that deterring it must remain a priority, since the actual thought of fighting China is so horrific.
Pull all these things together and there is nothing conceptually wrong about a Quadrennial Defense Review that, like this one, breaks little new ground. Its framework of the "four Ps" -- prevail in today's wars, prevent future conflict, prepare for future conflict, preserve the force -- is quite reasonable. It echoes the "shape, prepare, respond" motif of the last Democratic quadrennial review, Secretary of Defense William Cohen's in 1997. But back then, dealing with immediate war issues was more hypothetical than real, so the word of the day was "respond" rather than "prevail."
The military was not under as much stress, so there was less need to make "preserving the force" a central planning criterion. And the word "shape" perhaps underscored a somewhat more benign view of the international security environment, in which the Pentagon's job was to help strengthen an international security order that made war less likely. Perhaps the current mix of focal points is informed by a slightly less optimistic view of the nature of man and international politics.
The types of scenarios at issue are similar to every quadrennial review since Dick Cheney began the tradition back in 1992 with his "base force." Deterring and/or fighting two major contingencies remains the essence of the most demanding scenario envisioned by war planners.
The point is that the framework is reasonable but not provocative, solid but not innovative, cautious more than bold. It is interesting that a president who campaigned on a mantra of change would come up with this. And to my mind, it is somewhat reassuring as well. Military planning is not the place to make one's big rhetorical or symbolic mark in the world.
This is not to say that all is constant in defense circles. In fact, while the size of the military has hovered at around 1.5 million active-duty troops for nearly two decades, while big-ticket fighter jet and submarine and other aviation and shipbuilding and vehicle programs remain the core of the Pentagon's modernization agenda, lots has in fact changed. But the interesting thing about that change is that, particularly over the last 12 years or so, less and less of it begins with quadrennial review documents.
These reviews are probably not outliving their usefulness, but they are perhaps outliving their ability -- actual or even hypothetical -- to generate sexy headlines. The real action often happens in between quadrennial reviews, more often than not informed by developments on the battlefield more than in the great plate tectonics of international politics or high-level military strategy.
This process probably began in 1999. Then, the Kosovo war, while ultimately rather successful, revealed the limits of the Army's ability to respond to post-Cold War conflicts. As a result, Gen. Eric Shinseki became chief of staff of the Army, and he came up with big new plans for two kinds of new vehicles (the Stryker and the Future Combat System) to create a more mobile, "medium-weight" Army. Such ideas were codified in Donald Rumsfeld's 2001 Quadrennial Defense Review, but they were well in place before then.
Speaking of the 2001 Quadrennial Defense Review, it came out exactly 19 days after the September 11 attacks. While language was added underscoring the centrality of the homeland defense mission to the nation as final drafts were prepared for the printer, almost everything vital we would learn about how to handle the new age of terror was not in the review.
That included the use of special forces to help overthrow the Taliban in Afghanistan, the need for strengthened counterterrorism and counterinsurgency training for the ground forces, the need to take large-scale training of host nation militaries much more seriously, proper methods of using robotics as well as fast communications networks to create real-time response capabilities on the tactical battlefield, and of course the technological need to find ways to respond to the threat of improvised explosive devices.
As the Iraq war dragged on, real-world developments also necessitated a larger Army and Marine Corps despite Rumsfeld's initially strong preferences to the contrary.
All those things happened before Rumsfeld's next quadrennial review, in 2006. That document itself came out under a secretary of defense who did not really envision or even support the surge, and was implemented by Rumsfeld's successor, Robert Gates, who was hired to take a fresh approach to some of the intractable problems that Rumsfeld could not. So again, the quadrennial review was less than decisive.
And in budgetary terms, Gates' biggest impact came in April 2009, when his "springtime massacre" went after big-ticket weapons like Shinseki's Future Combat System, some missile defense programs, and large surface ships for the Navy. The February 2010 Quadrennial Defense Review has again codified what the annual budget process and other events had already formally set in motion.
So it's not a huge surprise to the specialist, and probably not exciting or Earth-shattering enough to be of great interest to the generalist. But all that said, I like this quadrennial review. Sometimes change works best in small, incremental doses.
The opinions expressed in this commentary are solely those of Michael O'Hanlon.