This is not an indictment of the US, it's just an assessment based on my own and other's extensive experiences with large, hierarchical organizations.
I'm not sure what would make it so high risk. The truth could easily be castigated and maligned as "conspiracy theory," a dismissal that most people in the Western countries will readily accept. The only people with the resources to investigate and find hard evidence would either be in on it (Western/NATO allies) or easily written off as pushing lies and propaganda (the Russians).