Russian President Vladimir Putin on Saturday oversaw a military parade commemorating the defeat of Nazi Germany in World War II on Red Square. Security was tight in Moscow as Putin spoke at the parade, even as a US-brokered three-day ceasefire eased concerns about possible Ukrainian attempts to disrupt the festivities. Putin, in power for over a quarter of a century, has used Victory Day, Russia’s most important secular holiday, to showcase the country’s military might and rally support for his...