Ukraine marked 1,000 days on Tuesday since Russia’s full-scale invasion, with weary troops battling on numerous fronts, Kyiv besieged by frequent drone and missile strikes, and officials preparing for Donald Trump to reclaim the White House in January. In a boost for the beleaguered country, U.S. President Joe Biden gave the green light for U.S. missiles to be used against targets deeper inside Russia, potentially limiting its options to launch attacks and supply the front. But the dramatic shift in policy may be reversed when Trump returns to the White House in January, and military experts cautioned that it would not be enough on its own to change the course of the 33-month-old war.