> Can you provide an example of a commonly used cryptography system that is known to be vulnerable to nation state cracking?

DES. Almost all pre-2014 standards-based cryptosystems due to NIST SP 800-90A. Probably all other popular ones too (like, if the NSA doesn't have backdoors to all the popular hardware random number generators then I don't know what they're even doing all day), but we only ever find out about that kind of thing 30 years down the line.