Well, I remember that it was Hilary Clinton that loudly made the announcement that the South China Seas was a core national interest for China.
The funny thing is, normally it's the Chinese foreign ministry putting out this sort of announcement.
Instead, it was Clinton broadcasting this to the world for days before any comment from the Chinese Foreign Ministry.
In Geoff Dyer's book, it's confirmed that Clinton "refreshed" her memory.
In the aftermath, look at how that move backfired on Clinton.
She thought China would fold and the other South China Seas claimants would flock to the USA for support and protection.
Instead, China owned the statement and built island bases which now dominate the South China Seas, without any reaction from the US.
And all the other countries in the SCS have taken note of this.
There's lots of other lessons here as well.