How to lose a war by splitting the difference.
Placing both of the new brigades destined for the south in Kandahar, moreover, would shortchange Helmand Province, nextdoor, where the Marines, British, and Danes have made substantial progress in recent months. Military operations there are complicated by the fact that Helmand is the center of the poppy production that feeds the opium industry which helps to finance the Taliban and corrupt the Afghan government. By putting one brigade in Helmand and one in Kandahar, McChrystal could likely consolidate and expand gains in Helmand, where the current troop-to-population ratio in the contested river valley is a reasonable 1:83 (though even with an additional brigade it would fall short of the 1:50 ideal). This would also have the benefit of consolidating the political partnership with Great Britain and Denmark--the two NATO allies most committed to staying the course in Afghanistan. Conversely, it would further shortchange Kandahar, which is a greater strategic priority.
The third brigade-sized unit, meanwhile, would be deployed among the volatile eastern provinces of Paktia, Paktika, and Khost--better known as Greater Paktia--where the combined strength of U.S. and Afghan forces is 8,200 and the force ratio is 1:79. The region is critical in many ways. The western parts sit astride the key Kabul-to-Kandahar highway, and the bowl-like area around Khost is just across the border from North Waziristan, the sanctuary of the Haqqani network, a Taliban-affiliated militia that operates in Afghanistan. The additional brigade in this region would make a big difference, not only consolidating recent gains but no doubt improving prospects for counterterrorism strikes against the Haqqanis, the younger of whom, Sirajuddin, is both a charismatic leader and highly radicalized.
The mission of the "reserve" brigade is less clear, although it is true that forces in Afghanistan have been stretched so thin that senior commanders have essentially been without a significant tactical or operational reserve with which to shape or react to events. But a reserve brigade is one thing in the context of a "Full McChrystal" surge of eight brigades and quite another in the context of a half-surge. First of all, under McChrystal Lite, chances are it wouldn't be in reserve for long. It would be far more likely to be committed, or tied down, as the result of having to react to an insufficient level of force across the theater; that is to say, it would more likely be used to prevent failure than to reinforce success. And there would likely be a temptation to parcel it out piecemeal around the country, lessening its impact and making it harder to support and sustain.
But this sequence of deployments--the one leaked to the Times--is surely a derivation from the sequence planned for the full complement of forces that McChrystal requested. Once he faces the reality of a cap on the troops available, McChrystal may rearrange the deck chairs. In particular, he may decide to mass all of the forthcoming brigades in the area that's most strategically vital and presents the greatest security challenge: Kandahar. Then there will be questions as to how best to balance the forces within the province between those focused on securing Kandahar City and those disrupting rural insurgent sanctuaries and lines of communication in the surrounding province.
But there's a very strong argument for a Kandahar-centric surge. Not only is Kandahar the Taliban's strategic center of gravity, but the key area of operations--those parts of the province that are contested--is the largest and most populous "battle space" in southern Afghanistan. Beyond the city-focused forces described above, there are now about 7,200 U.S. and Afghan forces deployed in the province. Three additional brigades in the Kandahar City area would very nearly provide the number of troops necessary to conduct a proper counterinsurgency mission; another brigade elsewhere in the northern portion of the province would help provide those focused on the city with increased room to breathe and strategic space in which to operate.