The US government was shutdown over the issue. It's the big thorn in the US - Mexico relations and it's polarized people in the United States and united people in Mexico. We are talking today about an issue of border security along the three thousand kilometer border that share between the United States and Mexico. It's now becoming examplified in Donald Trump's insistance on building a wall or rather completing a wall along the entire border and it's a heated debate on both sides of the borders. On today's From Mexico, Patricia Escamilla is a former professor at the National Defense University in Washington DC, a binational expert on security and the founder of the US - Mexico border security network.