'Chain of Command' - Gen. John Nicholson in Afghanistan

The National Geographic Channel continues its ambitious, eight-part documentary series "Chain of Command" on Monday February 5th at 9pm ET with episode 5, "Generations."

We've got a clip from this week's episode. Gen. John Nicholson, commander of U.S. Forces in Afghanistan, visits Camp Lion in Kabul for an urban warfare demonstration from Afghan troops.

The show aims to examine the war on extremism from as many perspectives as possible.In every facet of the war on extremism there is the recognition of how long the fight will take. In Mosul, the battle may be nearly won, but ISIS is still recruiting foreign fighters from far and wide, including the unlikely setting of Trinidad and Tobago, where Muslim leaders are the tip of the spear in the fight. The spread of ISIS ideology is a reminder that this is just the end of the beginning of the war.