Russia on Friday called a U.S. decision to not rejoin the Open Skies arms control pact, which allows unarmed surveillance flights over member countries, a political mistake that strikes a sour note ahead of a summit, Russian news agencies reported. The United States told Russia on Thursday it would not rejoin the pact, which Washington left in November, accusing Russia of violating it, something Moscow denied. The original decision to quit the pact was taken by the administration of then U.S. president Donald Trump and Moscow had hoped that Joe Biden would reverse that decision. Sergei Ryabkov, Russia’s deputy foreign minister, was quoted by the RIA news agency on Friday as saying that Moscow was disappointed but not entirely surprised by Biden’s decision. “It certainly does not make us ha...