TĐH: I totally disagree with this article and the experts it quotes as support.China has a policy of requiring any foreign vessel to (1) inform Chinese authorities of its intention to make an innocent passage through Chinese territorial sea, and (2) have Chinese permission prior to making such innocent passage.
USS Lassen did not inform Chinese authorities and did not have a Chinese permission, so that was not an innocent passage according to Chinese standards, and that explaines why China was so upset at USS Lassen passage.
That was a US Freedom of Navigation at the lowest level, which was a very good strategy. You don’t want to shock China so much with your first FON sail. Just enough to get China noticed. Then you can increase intensity in later sails.