Ukraine definitely does not have a sensible leader. In 2021 he declared both that "he does not like the Minsk agreements" and that "Ukraine needs to obtain nuclear weapons". After the start of the war, he insists that Ukraine be allowed to join NATO, which would automatically mean World War.
Alright, from his point of view, perhaps this is sensible: Ukraine stands to lose otherwise, so for him the World War might be preferable.
Ukraine's probably not going to join NATO. Obviously they really want to but it's hard to imagine a future where both Russia and Ukraine don't retaliate against even non-government and uncommanded (i.e. soldiers fire without authorization) attacks that go back and forth across the border.
Alright, from his point of view, perhaps this is sensible: Ukraine stands to lose otherwise, so for him the World War might be preferable.