At Monza last year Vettel did not need to go anywhere near as far away from Alonso's car as he did. If you compare what happened at Eau Rouge in the previous race Alonso left Webber the same amount of room as he left Vettel at Monza. It was just that Webber had the confidence in what Alonso would do whilst Vettel didn't. Either that or Webber has bigger cojones.