In regards to the Russian invasion of Ukraine, while some people who claim to be "anti-war" or "pro-peace" are covertly pro-Russia, most such advocates are simply naive to the fact that the Russian government would never negotiate peace in good faith (given their irredentist views and incredulous claim of the country being run by "Nazis").
While the parallels to "peace in our time" from the 1930s are clear as day, some people are unfortunately too isolationist, shortsighted, or simply tricked by Russian propaganda into thinking that Russia's territorial ambitions bear any legitimacy in the slightest, versus the democratic aspirations of a country that, for once, is actively requesting Western military assistance with the popular support of its people, in contrast to the pro-Western regimes propped up during the Cold War.
Beyond the importance of supporting democratic institutions, those who'd see the war concluded abruptly in Russia's favor (gaining territory with substantial grain production, natural gas fields, and several warm water ports), rather than continuing with full Western support until the country's borders are restored, should consider the lives that will be lost if Russia's ambitions are not kept in check, whether it be the continued invasion of Ukraine, or potential irredentist invasions Moldova, Georgia, or Kazakhstan to "protect" Russian speakers beyond the country's borders.