As you first wrote, "the documents prove nothing about Iran". Again, I agree the leaks weren't about Iran. They are about beating the drums of war with Iran.

Dodo suggested the drumbeats would not sound so loud if context was provided. But, I think when the American establishment is busy selling a war with Iran to the American public, then context is either non-existent or deeply discounted, and objectivity is not important. And since when has facts been part of Americans' decision to go to war? Certainly they played little or no part with the decision to invade Iraq or even Afghanistan. This is about ginning up emotion and lining up excuses.

That these nations haven't said anything against Iran publicly fits within the narrative. If the facts supported a war with Iran, then the war would sell itself.

For the most part, I think the American news coverage of the leaked U.S. diplomatic posts regarding Iran can be generally characterized as 'see everyone thinks Iran is a problem and have been secretly okay with the U.S. or Israel attacking them'. The implied suggestion is then those in the ruling class who may have been questioning the wisdom or legality of such a war, should cease their objections and the general public should support the start of such a war.