The number of undocumented migrants captured at the US Mexico border has reached a decade-long high, with the government predicting that the number will continue to rise. President Trump says the situation at the border is a national emergency. So, is he right? Ritula Shah is joined by three expert guests to discuss what’s going on at America’s southern border. How many people are really crossing it. And - is the asylum system working, or broken, or just under strain? (Photo: Mexican children at the US border. Credited: Herika Martinez/AFP/Getty Images)