This seems to have been the Biden and Zelensky plan Fight Russia until they are forced out of all Ukraine land including Crimea, then Russia will be so mad that they will overthrow Putin Can this happen?
Russia has been invading neighbors long before NATO expansion. Chechnya wasn’t about NATO. Georgia wasn’t about NATO. Accords and talks were used to allow him regroup. His issue isn’t NATO, it’s the idea that former Soviet states can exist without Russian control. That’s why he won’t stop. You see how messy the talks are between Israel and the Palestinians. That's because Israel, institutionally, for decades, has only ever planned to ratchet until they have everything. Putin is in the same, manifest destiny* dictates any sacrifice is just mode. So I would take this as read, accept the predictions of a 4 to 5 year conflict, absolutely no tolerance for sanctions busting. *"manifest destiny" in this context refers to a belief that Russia (or Israel, in the analogy) has a preordained right to expand and control certain territories, and that this right justifies its actions, regardless of the consequences for others. It implies a sense of historical inevitability and moral justification for aggressive expansionism.
My own godson in the UK is a mathematician (also read history) and gave up a cushy job to work for a pan-Europe military systems maker. What historical example do you have where Putin honored a peace agreement without using it to rearm? People in defense and STRATEGY, people who actually run the NUMBERS, are seeing this as a long-term conflict precisely because Putin has never honored an agreement in good faith. If Putin wanted peace, why did he break Minsk I and Minsk II? Why did he escalate during Istanbul? Why did he keep attacking after every ceasefire? What makes you think 'one more deal' would change anything?