By Sabine Siebold and Robin Emmott ON BOARD THE SUPPLY SHIP ELBE, Latvia (Reuters) – Hours after Russian missiles first struck Ukrainian cities on Feb. 24, German naval commander Terje Schmitt-Eliassen received notice to sail five warships under his command to the former Soviet Republic of Latvia to help protect the most vulnerable part of NATO’s eastern flank. The hasty dispatch was part of Germany’s scramble to send “everything that can swim out to sea,” as the navy’s top boss phrased it, to defend an area military strategists have long deemed the weakest point for the alliance. The vessels’…