Prisoner swaps, the latest of which took place in April, were part of US President Donald Trump’s effort to stabilize relations with Russia after years of diplomatic friction. Kirill Dmitriev, an aide to Russian President Vladimir Putin, told…

Prisoner swaps, the latest of which took place in April, were part of US President Donald Trump’s effort to stabilize relations with Russia after years of diplomatic friction. Kirill Dmitriev, an aide to Russian President Vladimir Putin, told…