The pro-US bias in this article is strong. It appears to be more of the same wardrum-beating, anti-Russian propaganda that took hold of the mainstream media towards the end of the US election.
On one hand, Russia does appear to have adopted a more aggressive military stance, especially with regards to Crimea and The Ukraine.
On the other hand, the present military stance of the US looks not unlike the full-tilt, batshit-crazy world domination plans of Germany during World War II.
It appears obvious to me that our current US military leaders are not above conducting false-flag operations for the purpose of gaining public support for foreign aggression, and it would not surprise me if they were responsible for this release of Iodine-131.
After all, they've done it before: https://en.wikipedia.org/wiki/Green_Run