Rehearsals are underway for Russia's upcoming Victory Day celebrations, when the country marks the anniversary of the Soviet Union's 1945 defeat of the Nazis with a massive military parade on Red Square.May 9 is one of Russia's most significant holidays, as many Russians are related to someone who was killed during World War II.This year, Victory Day is set to be one of the most-watched parades in years.It comes as the Kremlin still lacks a major win in its two-month war in Ukraine, which it bills as a "special military operation" to demilitarize and "de-Nazify" its neighbor.As a result, speculation that President Vladimir Putin could declare official war on Ukraine or order mass militarization has abounded.Here's a look at the ongoing rehearsals along central Moscow's streets: