Since the start of Russia’s war in Ukraine Moscow’s navy has blockaded Ukrainian Black Sea ports. Its impact is having ripple effects all around the world. Right now, more than 20 million tons of grain are stuck in Ukrainian silos. Russian officials have said that it could provide a corridor for vessels carrying grain if the West lifts sanctions. Ukraine and Western officials have called this a form of blackmail. Host Marco Werman speaks with Sidharth Kaushal, a research fellow at the Royal United Services Institute where he studies sea power and maritime doctrine.