[pax_et_bonum]

That makes sense, but it is still risky when your country now has access to global news. Russians overthrew their government twice in the last century. They could do it again. Why not target the biggest threats secretly (more secretly than a suspicious shooting and poisoning)?

Could be ego.

Maybe he's gotten to the point that he's so full of his own success that he doesn't think he can be overthrown and is choosing to intimidate more openly while also flaunting his power and control.

[wouldntbprudent]

Or maybe the use of some of these radiologic/biologic agents is very hard to control. For example, they might have been deployed in a certain situation, but their effects unintentionally caught up other people.

Say you are trying to poison someone with a radiological plug of some sort. That thing has to be transported, deployed, etc. In all that time it could be leaking radiation and poisoning bystanders (innocent and not innocent).