How can you negotiate with someone whose word is worthless?
you can’t - especially as you point out, he broke a treaty in 2014 and then broke the “frozen conflict” in 2022
Treaties broken on both sides. Recently Merkel admitted they (NATO) only agreed to the Minsk II agreements in order to buy time to build Ukraine’s army. IN response to her admission, Putin said “Trust was lost.”
When these litanys against Russia surfaces, it helps to remember NATO broke treaties too. They each want what they want - the Ukraine simply wouldn’t stop killing ethnic Russians living in Eastern Ukraine.