One thing that can be done to lessen the possibility of the US having done this is to investigate the site using ROV’s or divers if possible to sample the Ocean floor near the breaks. If the damage was done by a mk 48 ADCAP torpedo or mk 50 lightweight torpedo shot from a fast attack Submarine, there will be traces of ‘Otto fuel’ residue in a thin orange layer on the bottom. Otto fuel is a torpedo fuel used by the US, UK, the Netherlands and Australia which creates it’s own oxygen to burn. It’s by product is cyanide gas. When a torpedo hits, any unspent fuel sinks to the bottom. There is ALWAYS leftover fuel which does not perish in the explosion. It coagulates and reconstitutes similar to what happens in a lava lamp. The traces of Otto fuel do not disperse or delineate over time. Studies have shown that this fuel layer can remain for years and is highly carcinogenic. It remains in a thin layer just off the bottom as it is heavier than water and insoluble.
Should be doable to investigate and determine who did this from various standpoints. I don’t believe the truth is coming out anytime soon. The silence is telling.