Obama pronounces Pakistan as the locals do. Taliban, locally, is pronounced taa-li-baan, with a soft T sound that no American I know seems to be able to differentiate from a hard T sound. It’s a sound that I think doesn’t exist in the English language, or at least I’m unable to find a word that uses it, to be able to explain the difference to my friends.
The closest I can come to an explanation is this:
Say tree. Now say three. See where your tongue is when you say three? It’s not the same place as tree, right? Now say T with your tongue at the the position where you start the word three. That’s a soft T sound. Am I making any sense?
Next time you meet a South Asian friend, ask them to pronounce a native language word that uses a soft T and a hard T, and see if you can make out the difference. Chances are, you can’t.