Ukraine on Saturday vowed to triumph over Russian “darkness” as it entered a new year of war weakened by a lack of Western aid and with Moscow emboldened by fresh gains. To mark the second anniversary, a virtual summit of G7 leaders was due to take place at Kyiv’s Saint Sophia Cathedral later Saturday with Ukrainian President Volodymyr Zelensky attending. When Russian President Vladimir Putin announced a “special military operation” at dawn on February 24, 2022, many expected victory within days, but Ukraine fought back, forcing Russian troops into humiliating retreats. Since then, however, Uk…