Russian President Vladimir Putin delivered a speech at a packed soccer stadium on Friday praising his troops for fighting in Ukraine. Coverage of his speech on state television was unexpectedly interrupted by what the Kremlin said was a technical problem with a server. Speaking on a stage at the center of Moscow’s Luzhniki Stadium, Putin promised to tens of thousands of people waving Russian flags and chanting “Russia, Russia, Russia” that all of the Kremlin’s aims would be achieved. “We know what we need to do, how to do it, and at what cost. And we will absolutely accomplish all of our plans,” Putin, 69, told the rally from a stage decked out with slogans such as “For a world without Nazism” and “For our president.” Many of the Russian slogans used at the rally incorporated the “Z” symbol that Russian forces have used as a motif in Ukraine. One …