Is this really none of the USA or UK's business?
http://en.wikipedia.org/wiki/Budapes...ity_Assurances
When governments sign agreements everyone involved is expected to hold up their end all the time, not just when it suits them or when convenient.
The word of the worlds nuclear powers (the USA and the UK included) is as worthless as the paper and ink used to author and sign the agreements, treaties, pacts, etc they make.