U.S. President Joe Biden¡¯s sudden appearance in Kyiv¡¯s presidential palace on Monday morning was intended first as a morale booster for shellshocked Ukrainians in the midst of a bleak winter of power outages and a bitter war of attrition.

But it was also the first of several direct challenges on this trip to Russian President Vladimir Putin, who a year ago this week believed the Ukrainian capital would become Russian-controlled territory again in a matter of days, moving Putin closer to his ambition of restoring the empire of Peter the Great.

¡°Putin¡¯s war of conquest is failing,¡± Biden declared from the palace, his very presence there, alongside Ukrainian President Volodymyr Zelenskyy, meant to symbolize Russia¡¯s failure to take a capital that today remains brimming with life, its restaurants overflowing even as warning sirens blare.