Personally, I think a completely senile president totally depedent on 'aides and advisors', with access to the nuclear codes and 'football'... IOW kindly daft grandpa #Biden, 'shredded' those norms.

"John Simpson (whoever that is. His title is "World AFFAIRS Editor"): 2025 could be year for the history books as #Trump shreds global norm"
https://www.bbc.com/news/articles/cd0ng4eyr3xo