mexico border is a necessity. tom. tara, thank you. and this programming note the latest reaction to the president s emergency declaration tomorrow on this week with abc s martha raddatz. overseas now, we turn to the desperate fight for the latest isis stronghold in syria. the human toll, high. the images coming in. abc s foreign correspondent james longman taking us through the scarred towns that make up this battlefield. reporter: rubble and dust the isis legacy. it once spanned two countries and attracted thousands of extremists from all corners of the globe. tonight, the so-called caliphate is reduced to about 7,000 square feet of freezing mud in southeastern syria, where 1,000 or so isis fighters are in a standoff with coalition forces. today, we drove out to the towns nearest the frontline. we saw why victory can t be called just yet.