The Panama Canal is one of the most important places in the world. This engineering marvel transformed global commerce and solidified the USA's geopolitical power, but it’s currently the center of a high-stakes international standoff. First built by the U.S. more than a century ago, it is now a symbol of Panamanian pride. But President Trump is now threatening to 'take it back'. Trump claims that China now controls the canal- but is he right? Griff Jenkins heads to Panama to find out.