I might be biased as a Webber fan, but I believe that RB must get behind him now “for the championship”.
Vettel is 25 points behind Alonso, while Webber is only 11 – with two races to go. Brasil strongly favors Webber.
In the constructors, RB is now only 27 points ahead of McLaren. They are lucky that Button had a poor weekend, or they could have ended up with a much slender lead.
Webber must win Brasil, and Vettel has to be there to back him up and take points away from Alonso. There is too great a difference in points between finishing first and second for Red Bull to risk Vettel taking those 7 points (between 1st and 2nd) away from Webber.
If Alonso wins either of the two remaining races, he has pretty much taken the title. Webber would need to finish second to Alonso winning, and then win the last race with Alonso DNF’ing to take the title. If he finishes second and Alonso DNF’s, they would be tie on points (with Alonso winning).
Webber must win, Alonso must not win, and Webber absolutely must, at the least, finish ahead of Alonso in the two remaining races (and finish on the podium). Vettel must also assist to get Alonso as far down the field as possible. For eg. if it is Webber 2nd Alonso 3rd for the remaining races, Alonso wins.
Vettel would depend on other drivers not finishing races and not winning to have a shot at the title, so I think it is important for RB to get him helping Webber and taking positions/points away from Alonso (if they finish WEB -> VET -> ALO for the last 2 races, regardless of in which positions or gaps between them, WEB takes the title)
This is so close but it is agonizing, no matter how I run the numbers, outside of WEB winning the last two races, his title depends on VET finishing between him and ALO. Argh!