What/who are the prominent pacifist movements/organizations/thinkers in XXI century and what is their position on the conflict in Ukraine?
Much of the public and political discussion about the conflict in Ukraine is grounded in the concept of just war. Indeed, the initial anti-war sentiment was aimed only against Russian "special operation"; however, waging war by Ukraine and the support thereof by the West are considered largely justified, and those who volunteered to fight/kill for Ukraine have been largely treated as heros, and the pacifist attitudes have been even denounced.
One could agree that idealistic pacifism and/or non-resistance to violence is a no go for Ukraine. However, pragmatic pacifism seems quire relevant: it is unlikely that Ukraine will be able to liberate all of its territory, which means that Ukraine and its allies will eventually need to seek an accommodation with Russia, lest countless Ukrainians and Russians continue to die in meaningless fighting. (Even if Ukraine were to regain the control over all of its territory, Ukraine and NATO will still need to coexist with Russia.) Politically, the question of accommodation with Russia imposes itself not only from moral point of view, but also due to the economic hardships that the war brought to the world, particularly to Europe - in this sense pacifism could be a moral justification for negotiations with Russia.
To return to the question: I would like to learn more about modern pacifism, its views on the conflict in Ukraine, and whether any prominent western politicians have expressed opinions in favor making concessions to Russia in order to end the war.