Istans:
1. Afghan: Since we're waging a massive war there with a goal of toppling the government and destroying an entrenched network of foreign terrorists, this one isn't too hard to figure out. Enemy.
2. Pak: Their military government has kindly allowed the use of Pakistan as a staging ground for US military operations in Afghanistan, but their PR spin to their own citizens is that they're only allowing us to use Pakistan for search and rescue missions. There's a robust Islamic fundamentalist movement in Pakistan, and our military being there fires them up. Friend, but they wish we'd hurry up and leave.
3. Uzbek: They're Muslim, but decades of Soviet-style socialism (and vodka) means they've got no time for fundamentalism or the Taliban. So they've let us base the US Army's 10th Mountain Division there, which is great for us because they share a border with Afghanistan. By the way, where are the first nine Mountain Divisions? Friend.
4. Tajik: They share a border with Afghanistan, hate the Taliban, and are closely allied with Afghanistan's Northern Alliance rebels, many of whom are ethnic Tajik. So they're letting us use bases there. How nice. Friend.
Non "Istans"
If and when our military turns its attention to an Arab country like Iraq, this will all change. But for now Saudi Arabia is a friend with military bases for us and delicious crude oil. Ditto United Arab Emirates, Kuwait, Qatar and Oman. Egypt doesn't have oil, but we're allied with their government if not their people. Iran doesn't like us or Taliban, but they're keeping quiet for now. Turkey is a strong ally, member of NATO, and will be crucial if we battle Iraq again. And there's always our regional superfriend, Israel.