No one is saying he is alive.
Most are saying he died a long time ago.
Hence the shitty VHS tapes from years ago, and lack of contact.
The last time he appeared he looked sick as fuck, and its widely agreed that he may have died from his kidney disease many years ago.
This is pretty much seen as a stunt, here in Europe, a way of breaking the "news" that he is dead, and making it out that America "won". I would expect America to pull out of Afghanistan over the next few weeks now, as "the job has been done".
In reality, he died ages ago, but this way you can end the war without looking weak.
I mean, come on, chasing the man down for ten years, killing all his followers, 900,000 civillians, and when you finally catch him....
...you fly his corpse hundreds of miles to the other side of the country to bury him at sea, to avoid offending his religion?