It's at least the most likely option. The US had most to win from this. This removed Putin having the pipeline as a negotiation tactic. Putin could already tur

It's at least the most likely option. The US had most to win from this. This removed Putin having the pipeline as a negotiation tactic. Putin could already turn it on and off as he pleased. For the US there were no big consequences either as they would not lack gas. And they could export their LNG. And having an agent or two rent a boat with fake passports cannot be that difficult and then load it with a Navy SEAL team or whatever divers (even civilian) and place the charges cannot be anything that is extremely difficult. It's like 70-80m. Below link shows that 100m is "One of the recommended technical diving limits. Maximum depth authorised for divers who have completed Trimix Diver certification with IANTD[9] or Advanced Trimix Diver certification with TDI." https://en.wikipedia.org/wiki/Deep_diving https://en.wikipedia.org/wiki/Deep_diving And regarding the theory that it is Ukrainians, I would think Ukrainians would have better things to do. If they wanted to and where capable to do some high stakes thing they should have blown up the bridge from Crimea or something similar helping them limit the invasion.