Uzbekistan is a state bordering Afghanistan. Allies of the Taliban, most notably the Islamic Movement of Uzbekistan, move back and forth across that border to attack NATO forces in Northern Afghanistan, particularly the province of Kunduz. Some elements of the IMU are now closely affiliated with Al Qaeda and have been linked to plots against the West, including a reported plot to attack bases and hotels in Europe a la Mumbai on specific orders from Osama Bin Laden.
Uzbekistan is ruled by a brutal autocrat leftover of the Soviet Empire named Islam Karimov. His rule has been rated one of the most brutal dictatorships on Earth, routinely engaging in the systematic torture, murder, and even rape of political opponents.
Under George W. Bush, who similarly professed blissful ignorance about the precise ins and outs of the world, we de-emphasized our logistical military presence in stable democracies like Germany, Italy, Korea, and Japan in favor of bases 'closer to the front' which tend to be autocratic, unstable, and subject to how much ass-kissing we give the local dictator.
Islam Karimov was one of these dictators. Who while we were using his country as a base, launched a brutal Tianamen style crackdown on protesters in his own country, leaving hundreds of innocents dead. The Bush administration largely looked the other way, but what little protest Bush did raise to Karimov was enough to get him to kick out our forces wholesale.
As a result, we became more reliant than ever on moving NATO's supplies through Pakistan, which meant they had to travel through the AfPak border to get to Kabul or Bagram airbase. Translation: our supply lines ran right through the heart of enemy-held territory. Which would be like if Patton's supply lines in WWII had to go through Germany before they could get to France.
Naturally the Pakistan Taliban's new hobby was raiding and burning these supply convoys, sometimes taking trophies for themselves in the form of brand new up-armored Humvees, helicopter engines that would fetch a pretty penny on the black market, or just more practical items like MREs, body armor, and Afghan army uniforms for infiltrators who want to kill US soldiers up close.
A bolstered dictator, a massacred democracy movement, greater hatred of America, and a tougher, more determined Taliban.
All that and more because the previous President didn't know anything about the President of Uzbekistan.