I know it's become fashionable to transplant the familiar mantras of the Iraq War ("colossal mistake", "never should have started to begin with", "they all hate us") to Afghanistan, but these are two very distinct wars. And Afghanistan itself has been two distinct wars.
I vehemently opposed going into Iraq. I marched in protests in Washington multiple times in 2002 and early 2003. I never opposed going into Afghanistan. I wasn't happy to see us going in, but it was something that needed to be done. And we more or less won that war by mid-late 2002. The Taliban were routed, the Northern Alliance was in control of most of the country, and opium production had dropped to almost nothing. We still had some work to do pinning down the last remnants of enemy forces along the Pakistani border, but that was an achievable goal, especially with sufficient pressure on Gen. Musharraf.
Then George W. FUCKING Bush made what will long be regarded as one of the worst strategic errors since Hitler invaded Russia. He pulled out 90%+
of our forces out of theater so he could go dick around in Iraq. We committed one of the cardinal sins of geopolitics: we created a vacuum, and then failed to fill it. And in the absence of a real troop presence and a committed effort to build institutions of governance and public services, the country went to Hell in a handbasket. Now, it could be said that the country was already Hell in a handbasket and pretty much had been since 1979. But that doesn't excuse the US. We made a promise to the Afghan people, and then we skipped town. And so the Afghans learned the same lesson the Kurds learned after 1991: don't trust the Americans, because they'll leave you hanging at the worst possible time.
Now we have a resurgent Taliban, Osama and Co. have disappeared to God-knows-where inside of the NWFP, the Afghans don't trust us, the warlords have had time to retrench their regional control, and a somewhat cooperative Pakistani dictatorship has been replaced with a fractious and uncooperative Pakistani democaracy. Musharraf may have been a bastard but he was our bastard, as the old saying goes.
Is the war winnable? I don't know. Honestly, we may have f**ked things up so bad by our six-year hiatus that it's not salvageable. But as long as there's any reasonable probability for success, I feel that we need to continue. But we need to do it the RIGHT way, not this half-assed, war-on-the-cheap that we've been doing for too long. Afghanistan needs to be our #1 foreign policy priority, and it needs to be on the front page, every day.
What kills me is that so many on the Left stood under the "Iraq is a mistake, we need to be focusing on Afghanistan" banner when criticizing Bush, and all through the 2008 election cycle. And as soon as Obama was elected, they act shocked and betrayed that we haven't packed up shop and left Iraq *and* Afghanistan.