When Russia annexed crimea in 2014 (phase 1 of the current war) the response was sanctions because no one wants WW3.
Russia realized it can keep taking territory if it does so slowly because everyone is afraid of a bigger war and sanctions don't bother the Russian elite that much, so in 2022 they start phase 2 and absorb the additional sanctions.
Trump has a new capitulation deal for Ukraine in hand, possibly pre-approved with Russia, but Zelensky either backed out of accepting the terms or was otherwise surprised about the details and didn't play ball with Trump; possibly because it included him losing a lot of face.