If Putin agrees to a ceasefire and a de-escalation, it seems obvious to me that three factors stand out in an explanation: one – and this is by far the most important – is the armed resistence of the Ukrainian army and people; another is the further congealing of a Ukrainian identity. People don’t die for a country unless their believe it’s theirs. The last is the provision of certain types of aid, especially military aid, to the freedom fighters by NATO.
NATO’s provision of military hardware to the war effort is a difficult needle to thread considering that it runs the danger of escalating the conflict miltarily and geographically. But so far it has been done judiciously by and large. In its absence it is hard to see how the Ukrainian army would have fought Russia’s army to a standstill. And in doing so give some hope that Putin won’t achieve his war aims and Ukraine will remain a sovereign and independent state.
That said, a diplomatic-peace offensive by the Biden administration is very much in order.