Kiev and Moscow were facing their worst crisis in years on Monday as Ukraine and its Western allies demanded the release of three ships fired on and seized by Russia near Crimea. Russian vessels boarded and captured the ships on Sunday, accusing them of illegally entering Russian waters off the coast of Crimea in the Sea of Azov. Ukraine’s military was on high alert and parliament was to vote Monday on a request from President Petro Poroshenko to impose martial law for 60 days.