US basketball star Brittney Griner was released from a Russian prison on Thursday in a dramatic high-level prisoner exchange with an arms dealer nicknamed the “Merchant of Death”. American officials said two-time Olympic gold medalist Griner was swapped with Russian arms dealer Viktor Bout. The swap, at a time of heightened tensions over Ukraine, achieved a top goal for President Joe Biden, but carried a heavy price — and left behind an American jailed for nearly four years in Russia. The deal, the second such exchange in eight months with Russia, procured the release of the most prominent Ame…