I have to say, given Russians, I like the second solution better, if some three-letter agency doesn't come muscling around and tell them to knock it off.

Oh, shit, given Russians? No. Do the grey hat solution. It's quick, it's permanent, and it is a loud and clear signal to the nekulturniy degeneraty that hey, two can play at this game, and that bullshit will not be tolerated. Playing it the first way gives him *time* to take revenge... and this time he might get away with murder. Yeah, he'll be PNG'ed and sent to Siberia anyway, but at the loss of one of your people.

Yeah. Slip him a mickey, tie him up, drop him at the Afghani Embassy or the like... end of problem.