The backstop will only come into play if the GFA is threatened because a deal that protects the border cannot be agreed
Thought it would come back to the backstop, again. So no progress made.
EU wants the backstop to protect its Single Market and Customs revenue. UK does not want the backstop as it allows EU to lock UK into the Customs Union and Single Market forever.
Essentially neither the EU nor the UK negotiators trust the other. Not too surprising considering it is effectively UK vs an alliance of France and Germany.
France still pissed off because;
French is not the World's first language
English archers wiped out the French at Agincourt despite being massively outnumbered
So very important that France eventually gets over UK after being hammered by UK for centuries
Germany still pissed off because:
UK was instrumental in the defeat of Germany in both WWI and WWII
England won the World Cup football in 1966
So very important that Germany eventually gets one over the UK as revenge.
UK
Totally unacceptable to go cap in hand to the French or the Germans as UK has beaten both France and Germany so many times in the past it can do it again.
UK ruled the waves before WWI. In WWII ruled the skies when the Spitfire pilots achieved a 2 to 1 ratio of victories over the German pilots.
As Churchill (who Johnson wants to copy) famously said
"We will fight them on the beaches if necessary"
So it is all a game.