If Putin admits that he mad e a mistake and withdraws totally out of the occupied Ukraine territory then I'm sure that Zelenskyy would agree to a ceasefire.Yes, just like many people spoke out against George Bush in the Iraq War .
He was the one who invaded a sovereign country. And way back in the era of
Johnson and Nixon many people took to the streets to protest against the
Vietnam war.
In the same anti-war spirit we could give moral support to Ukraine
and send them humanitarian aid. Finding a way to bring on ceasefire
with diplomatic means is also an alternative to cheering (and financing)
Zelensky and Ukraine to fight to the bitter end.
Ukraine war will leave Russia too destitute to escalate the war into Europe.
Even before the war Russia was economically a weak country by the standard
of European nations. Putin is a bad man but not a lunatic. He would understand
he stands little chance to win a war against NATO which could bring him down
back home.
However, Putin is not willing to concede any of the Ukraine territory. The quicker that the Russian citizens start to oppose Putin's war, then the more likely that it a better outcome will prevail.
But Putin's ego is all about trying to restore what was once the Soviet Union, and hence Ukraine was the first hurdle that has not gone too smoothly as Putin's promise to occupy the whole of Ukraine in around two weeks!!