Earlier quoted context omitted.
This has nothing to do with corruption. People talk even without getting paid. Not everyone realizes what they're saying is important or will become important in the future. Most of the time it's just background information. Also, there's not necessarily an element of "great personal risk". It may just be social or embarrassment or minor damage to a career. If some flunky at a Peruvian consulate has a bit too much to…
"Man, I really need to watch what I say to the Americans." Given the degree of subterfuge the US has facilitated in many of these countries, over the years -- most of these folks already knew that.
And I think you're mostly jumping at shadows here. Diplomacy is a lot less interesting and less nefarious than you seem to believe.