They likely can, we learn only about the cases where it blows up.

Errr, They (probably) did that a few weeks ago:

http://www.bbc.com/news/world-europe-43443271

You've got to be kidding. The recent chemical weapon attack was done for the shock value, because they literally do not give AF about the consequences. It's Putin flexing on the world stage.

> Russian ops can't even poison an expat without severe consequences

Only because of the public backlash against the local government last time they were known to have poisoned someone in the same country without consequences.

> kidnapping or murdering people outside of Russia would be an act of war

It would, but that hasn't stopped them before.

What consequences though? There's a bit of posturing regarding a recent case, but I haven't seen too much of consequence.

Like they couldn't poison Litvitenko with polonium and Skripal and his daughter with a nerve agent a few days ago?