Cross-posté sur le site de l'Alliance Géostratégique, voici un billet en anglais, premier d'une chronique que je tiendrai régulièrement.

On October 3rd, the Center for a New American Security, which some refer to as "the Obama administration's favorite think tank", published a quite interesting study on defense reform options for the U.S. in light of soon-to-come budget reductions. The report, called “Hard Choices: Responsible Defense in an Age of Austerity” is interesting because it puts forward four different force structure options for the U.S. armed forces, depending on the extent of the cuts to the Pentagon budget.

CNAS_Report_HardChoices
Beyonf the specifics of the report, what is interesting is to see that the study basically suggest to emphasize aerospace and sea power, at the extent of land power. In other words, while the U.S. Air Force and Navy are if not unscathed, at least preserved by the force structure scenarios, the U.S. Army and Marine Corps are to be put back to their pre-9/11 strength, if not reduced even more. Conventional ground capabilities, especially, are to be considerably reduced, and most of the U.S. still massive armor and artillery arsenal would be put in the hands of reservists, active forces retaining only lighter forces.
The fact that such a study can be produced by what used to be the go-to place for counter-insurgency advocacy – a doctrine which is, even under the best circumstances, manpower-intensive and excessively reliant on land power – is a testimony of how the U.S. defense policy has changed since the end of the Bush presidency, with its emphasis on extensive COIN campaigns in Afghanistan and Iraq.
More profoundly however, it's also a sign that land power has few advocates in the so-called western world right now. In fact, air and sea power seems once more to be the strategic tool of choice when it comes to foreign intervention, as the recent war in Libya demonstrated. This is especially true when it comes to the United States, in which most defense specialists now argue that Asia and the Pacific are the most likely hot spots in the next decades.
In this context, as in the 1990s, there seems not to be a lot of reasons to retain large ground forces, except for special forces and a few conventional units for strategic raid-type missions. As it seems, and as even COIN seems to suggest, the future of land armies is constabulary missions.
Or is it ? Time and again since the beginning of the 20th century, theoreticians have argued that land power was obsolete for war and only useful for international police and constabulary duties. Time and again, they have been proved dramatically wrong. From Douhet to nuclear war theorists to current U.S. defense analysts, the virtue of land power was only to occupy ground: the function of destroying the enemy being much more efficiently carried out by ships – when they are aircraft carrying or cruise-missile equipped platforms – and airplanes.
Land forces, however, are not so much about destroying enemy forces and occupying ground than they are about closing with and shaping the enemy system in such ways that air or missile strikes can't. Put simply, land forces can shape and dislocate the enemy, infuse him with an effect of shock and yes, when necessary, rip him of his sovereignty over his own territory by physically undermining the enemy's political authority and legitimacy. Put another way, land forces can outmaneuver the enemy system, put it into shock and dislocate him. Naval and aerospace forces, on the other hand, can only strike elements of the system.
If the system is simple and fragile enough, like a terrorist cell for example, quick and precise strikes, be they bombs and missiles or special forces “direct action” missions, are enough. If however the enemy as at his disposal a political and social apparatus, and is in effect a complex system, strikes are not enough. In 2006, despite extremely effective airstrikes over Lebanon, Israeli forces learned this lesson the hard way. They had to reluctantly commit ground forces to the fight, and since these forces had lost their edge in conventional combat, their performance was far less than could be reasonably expected from what used to be the Middle East best armed forces.
Since then, the Israelis have once again put an emphasis on strong conventional fighting capabilities, recognizing that tactics are neither regular or irregular: once one is in a firefight, it is fire and maneuver that carry the day. Having heavy armor then and lots of firepower, especially direct fire, certainly doesn't hurt.
What is sure however is that the commitment of ground forces is going to be, more than ever, a last resort option: with COIN operations coming under increasingly harsh review, justifiably so since they are no more than post-colonial police operations with bigger guns, and full-scale conventional war, even for limited objectives, being a sure way to pile up casualties, U.S. and European governments are likely to prefer air, naval and special forces for future contingencies.
Until, that is, they cannot do anything else but commit conventional ground forces to the fight. War, after all, has a nasty habit of forcing one to implement last resort measures, especially when one doesn't want to. For the next centuries or so, massive ground forces will have to remain available. No one, however, is saying that they must be professional active forces: conscript or reserve forces will be more than enough, since they would both increase the threshold of their commitment in limited contingency operations and be sure to be committed anyway if the stakes are high enough. The question thus is not so much whether or not ground forces are necessary. They are and will always be. The question is more whether or not massive, professional ground forces are the way to go. The answer to this question is probably a qualified “no”. A small professional cadre, and mobilization plans, could come back to haunt 21st century planners like they have for the past two centuries. While apparently archaic, selective mobilization might indeed be the way to the future when it comes to land power.

Illustraton : couverture du rapport "Hard Choices", Center for a New American Security