It is hard--no, impossible--to see any strategic or military reason why President Barack Obama would decide to remove thirty thousand surge troops from Afghanistan by September 2012.
The full surge force only arrived in late fall of 2010. Since then, the troops have done yeoman work in securing the southern Helmand and Kandahar provinces, where the Taliban was born and which it has long dominated. But, as the military likes to say, those gains are "fragile and reversible." They are also incomplete.
Obama, recall, sent the bare minimum number of reinforcements requested by General Stanley McChrystal. Fifty thousand more troops would have given commanders in Afghanistan far more flexibility and margin for error. With only thirty thousand extra troops, bringing the total U.S. troop presence to one hundred thousand, NATO commanders had to economize in numerous areas to achieve critical momentum in the south.
Regional Command East--the vast, mountainous region between Kabul and Pakistan where the Haqqani Network, the Taliban, the Hezb-e-Islami Gulbuddin, and al-Qaeda have their strongholds--never received enough personnel to carry out the kind of manpower-intensive security measures that have been implemented in Helmand and Kandahar. The expectation of General David Petraeus had been that, having secured the south in 2011, he would then shift his focus to the east and secure that too in 2012 and 2013. This would have prepared the way for transition to Afghan control in 2014 as agreed at the NATO summit in Lisbon last fall.
Now all those carefully orchestrated plans made by Obama's hand-picked commanders have been cast into serious doubt by his decision to pull out a third of U.S. troops while the summer 2012 campaigning season is still underway. Not only will this make it much more difficult, if not impossible, to secure eastern Afghanistan; it will make it hard to hold on to gains in the south.
It will also make it difficult to continue growing the Afghan Security Forces because newly trained police and soldiers require close mentoring by coalition forces. There will now be fewer foreign military personnel capable of doing that.
It is not just a matter of a third fewer American forces. By signaling retreat, Obama has also given the green light for U.S. allies to scuttle out as well. The day after his speech, President Nicolas Sarkozy said he will begin pulling French troops out as well.
It is possible that Obama's announcement will set off a precipitous loss of confidence in the war effort not only on the part of Americans and our allies but also in Afghanistan itself where Washington risks forfeiting the operational momentum that U.S. troops have fought so hard to regain over the past year. If that is the case, the political advantage that Obama no doubt hopes to derive from his announcement will prove illusory.