| In our ongoing series, Issues That Matter, we take a look at our nation's fight against ISIS. The State Department says ISIS has lost about 78 percent of its territory in Iraq and 58 percent in Syria since its peak in 2014. Nearly one-third of those losses have happened in the past six months. Brett McGurk, special presidential envoy for the Global Coalition to Defeat ISIS, joins "CBS This Morning" to discuss how ISIS is fighting for their life, "block by block." McGurk served under three administrations and just returned from a 12-day trip to the Middle East.