Would the hard border that would come up in a "no deal" Brexit (between the Republic of Ireland and Northern Ireland) be violating any binding agreements that the UK has signed? (And the same goes for question for the Republic of Ireland and/or the EU.) Or is it merely politically "unacceptable"?
There's video by the European Parliament which mentioned the Good Friday agreements and some EP resolution. But how binding are these with respect to actually mandating a non-hard border? And what do they actually prohibit or demand with respect to the border?