The Russian security agents were smirking. David was panicking. As the hours-long interrogation dragged on, he worried they would send him back to occupied Mariupol and into the ranks of Russia’s army. Having lived through three years of Russian rule in the southern port city, he and his friend Nikolai -- both teenagers -- were fleeing after being sent call-ups for Russian military service. JOIN US ON TELEGRAM Follow our coverage of the war on the @Kyivpost_official . At a checkpoint on the way