All that needs to be said to demonstrate that it was the US is that both Germany and Sweeden had separately investigated the crime scene and both REFUSED to disclose their findings and BOTH cited 'National Security Risk/Threat' as why they wouldn't release their investigation's conclusion, which indicates that it wasn't Russia and that it is guarantee to have been their Allies, so you can cross 'that Greek tanker' off the likely suspect list also, leaving only the US and their 'training' exercises in that area. Sweden claimed to have recovered two(iirc) unmanned sea drones, plus that goes hand in hand with comments made by the empire puppet, bidet, and the fat cow who was handing out candy during the US led coup in Ukraine, NullandFugly and to conclude the CIA has already blown up a Russian gas pipeline in the 80's also.