You summarized better what I was trying to say. Tony was definitely pissed that Christopher was high and the baby could have been in the back. No doubt that's what inspired Tony. The point I was trying to make was that in terms of ruthlessness, the way he killed Christopher (plugging his nose) was NOT ruthless. It was just a perfect opportunity for Tony to kill Christopher without implicating himself.

I thought that one of the most potentially ruthless killings that didn't happen was during "Remember When." Tony kept pressing Paulie to confess that Paulie was the one who told Johnny Sacc about the "90 lb mole" on Ginny. So much so that Paulie was on a boat alone with Tony and started freaking out. If I recall, he even flashed back to when they whacked Big Pussy on the boat. Paulie was definitely ready to soil his pants. And I think had Tony killed his friend Paulie, it would have been among the most ruthless things Tony had ever done.

Especially when in that episode, Tony told Paulie that there were times he wish Paulie were his father growing up.

When Tony hurled that beer at Paulie, Paulie was about white as a ghost.

RE: Christopher -- I do agree that it wasn't a ruthless killing on Tony's part (and I should have made that clearer).

Same here. Tony was more prickish in that episode -- wishing Carmela's spec house would collapse, screwing over Marie Spatafore with helping Vito, Jr., even down to how he treated Melfi with the missed appointments.