Back during the Clinton administration, we signed onto the UN drug control treaty. IIRC, CO and WA legalizing mj effectively put them out of compliance with that treaty. By doing it, they've established precedent that those UN treaties do not apply to the state governments, and that's going to complicate any enforcement of that small arms treaty Obama is wanting to sign.
Yep. Feds got a big ‘FU’ from CO and WA over mj. They’ll get the same with a small arms treaty, except it won’t be confined to 2 states.