Maybe I'm wrong.

https://www.economist.com/news/books-and-arts/21729415-it-was-underpinned-movement-make-waging-aggressive-war-illegal-and?fsrc=scn/tw/te/bl/ed/theliberalorderofthepast70yearsisunderthreat

So, this is the "economist".  I know that many newspapers are being outsourced to countries where English is a second language.  I've learned to skim through articles, there is supposed to be a beginning, middle and end.  However, the end is supposed to tie things up, or maybe put a question mark on an idea.  But, this first sentence of the last paragraph does neither for me.

"Ms Hathaway and Mr Shapiro are right to sound the alarm that the post-second-world-war consensus on the illegality of war is under siege."  Now, I hate war.  War is legal when voted on by congress.  When it isn't, the name is changed to something like a "police action".  For example, Vietnam or Korea.

So...what is the "illegality of war"?  What does that mean?

Asking for a friend.  😉