That would have been treated as an attack on NATO. Why perform a hostile act if a much cheaper threat works? Even if it only gets you 10% of what a successful hostile act gets you, it is worth doing because it is a lot less risky.

Gotta say this threat doesn't sound compelling. Who didn't know Russia could bomb a pipeline? Seems more like Russia punching itself in the face for literally no reason.

Also, given the climate now, if there was even a shred of evidence or any hint that Putin did this, US media and intelligence officials would be blaring that from every rooftop and every talking head would be "Russia this", and "Russia that". I think the relative silence speaks very clearly.

We also know that kidnappers can kill people. We take them a lot more seriously when they started sending ears in the post, don't we?