During his inaugural speech, US President Donald Trump threatened to "take back" the Panama Canal.  Built in the early 20th century, the waterway is a key maritime trade route.  The US relinquished control in 1999 in a deal that obliged the operator to charge ships fairly. We'll take a closer look at the economy behind the canal. Plus, Donald Trump is promising to significantly change the US's trade policy with tariffs.  But do these taxes protect domestic jobs and people?