Sen. Mark Kelly talks to CNN's Dana Bash about whether he thinks the second US military strike on a suspected Venezuelan drug vessel constitutes a war crime and, as a former Navy captain, how he would have viewed the order when he was on active duty. #cnn #markkelly #venezuela #boatstrikes

Caesar’s Double Siege: Starving Alesia The Battle of Alesia is perhaps the greatest military engineering feat in history. Facing a massive enemy force inside a city and an even larger relief army approaching from the rear, Julius Caesar did the unthinkable: he built two walls and fought two armies at the same time. This video covers: The Trap: Vercingetorix's retreat to Alesia. The Donut Fortification: Caesar's construction of the circumvallation and contravallation lines. Ancient Minefields: Th