Well, we can hardly keep politics out of the Eurovision song contest. I'd certainly agree if you're thinking of the World Cup. Success in such a major tournament seems to produce a feel-good factor which benefits ruling political parties.
Failure produces the opposite effect.
Also , the very act of hosting the World Cup or the Olympics gives a great boost to tourism because of all the spectators who come to watch their country and the opportunities to present favourable images to the media. Look how Barcelona prepared for the Olympic Games. Yet, there are surely some features of these events that are above politics . But both have nothing to do with sport. I think you're being too sceptical .