https://www.schneier.com/blog/archives/2007/11/the_strange_s...
Thread by someone directly involved on why the ISO rejected NSA ciphers in the past (hint: they refused to justify design decisions, lied, and attacked the credibility of people who had put out actually-secure crypto):
https://twitter.com/TomerAshur/status/988696306674630656
Either they're too incompetent to be trusted or are bad actors and should be treated as such.
I agree but am curious about one thing. If they aren't stupid won't they realize it's a terrible idea to embed weaknesses in standards destined to become so pervasive your own economy will rely on them (as well as your own military/intel)?
Also, history virtually guarantees that your most secret secrets are reasonably likely to become known to your adversaries and used against you with catastrophic consequences? Even if they could entirely subvert the standards process to plant their own backdoor that ends up everywhere, game theory dictates they might be creating their own greatest future weakness.
The Dual_EC_DRBG backdoor [1] is a asymmetric crypto based backdoor. Only the one who built the back-door has the key to access it. It's even impossible to prove the backdoor is there without knowing the key.
This way you don't weaken yourself or allies WRT 3rd parties when standardizing on that specific weakened algorithm (of course you need to closely guard your key).