This is an excellent, detailed, long twitter thread in 4 parts. I've linked the thread-reader version, or you can start from the first tweet, HERE .
QRD: In 1994 US submarine on exercise in the Baltic accidentally (?) sank a passenger ferry killing almost 1000 people. The Swedish government, and other Baltic nations who were set to join NATO, covered it up and blamed a design failure for the sinking. At the time, NATO was expanding eastwards. Since the fall of the USSR however, and with it the loss of the enemy NATO was established to defend against, this expansion seemed unnecessary to the public. The incompetence of the (apparent) accident apparently would have been a PR nightmare for NATO's pointless existence and expansion, at least under it's guise as a "defensive partnership". The cover-up was seemingly so crucial that actual survivors, who may have had witness testimony that would contradict the cover-up, were disappeared and/or apparently thrown back into the ocean (hours after being rescued and even cared for in hospital) to drown.
Crazy stuff.
Bollyn presents an alternative theory as to why the sinking happened in that article, much of it speculative in my opinion It seems to be similar to what Swedish boat engineer Anders Bjorkman writes about here:
http://heiwaco.com/news.htm
The twitter thread doesn't go in that direction so much, deals more in the practical specifics of the incident and cover-up. I hadn't seen it quite so articulately and succinctly laid out before. The twitter guy seems to be drawing from various sources including a book by an apparently American writer, Drew Wilson, that I can only find in a foreign language so far:
https://ipfs.io/ipfs/bafykbzacedovsnqmusd5hkvjmjtclmajs2l4sivldp7vlw4rvfdhhhckzd2cs?filename=Wilson%2C%20Drew%20-%20AUK_%20Parvlaeva%20%27%27Estonia%27%27%20hukust%2028.%20septembril%201994.%20a.%20teise%20nurga%20alt-No%CC%83mme%20raadio%20toimetised%20%282008%29.pdf
Looking for an English version.