> Its political and military move. Realistically only US and Russia

> have the capacity to do 3 attacks like this simultaneously.

No need to do 3 attacks simultaneously. An attacker could have placed explosives there some time ago and the detonated it remotely now.

Formar Naval Special Operator and now teacher in marine engineering and doctoral student at the Swedish Försvarshögskolan, Patrik Hulterström, alleged that "An experienced diver can in theory manage it himself" according to https://www.vg.no/nyheter/utenriks/i/4ozy8o/orlogskaptein-tr... ( in Norwegian).