Widmore sank the island by MYERZ

After watching this weeks episode 6x11 I came up with a theory about the island sinking.

By showing us the island underwater at the start of the season they wanted us to think that this was a direct cause of the bomb going off.

Anyone whos followed lost since the beginging should know that this is the writers using mis-direction)

Any way on with the theory,
I think the reason whidmore brought desmond to the island is because he knows that Desmond can change the past.(Danieal said this in season 5 "The rules dont apply to you Desmond)

When Jack and co set off the bomb in 1977 Whidmore was the leader of the others. After the bomb went off I think whidmore did/caused something to happen which in turn sank the island.

Whitmore wants to send desmond back not to stop the bomb going off. but to stop himself from causing the island to sink.
I dont think he wants to stop the bomb going off because this event HAS to happen.

Im sure this therohy is full of holes and im ready for it to be shot down. but I think its a pretty sound theroy.