What's our goal in Afghanistan?

"The Taliban in Afghanistan warned on Thursday they would attempt to derail next month’s presidential election, calling on Afghans to boycott the poll and urging them to “join the trenches of jihad”. Afghan and foreign troops are battling a growing Taliban-led insurgency across Afghanistan, with attacks escalating after thousands of US and British troops launched major operations in southern Helmand province this month. The increased violence coincides with campaigning for the August 20 poll, the second direct vote for president since the fall of the Taliban in 2001."

http://www.dailytimes.com.pk/default.asp?page=2009%5C07%5C31%5Cstory_31-7-2009_pg20_1

We invaded Afghanistan to capture and punish the terrorists who attacked us on 9/11/01.

Now, almost 8 years later, we're still there, increasing our presence, and serving as armed election monitors (of an election that will be won by racist, sexist, theocratic anti-democratic religious fundamentalists).

Why do we have any interest in any of that?