Yemen is home to al Qaeda in the Arabian Peninsula and Saudi officials are concerned the recent takeover of the capitol by Houthi rebels will give the terrorist group a greater foothold.
Robertson discussed the situation and his experiences covering global conflicts during his 25-year career in a wide-ranging "ask me anything" chat on Reddit.
Here are the highlights from the hourlong conversation. Some of the posts have been edited for grammar and clarity.
Q: "I hope you don't mind answering a really basic question. What exactly is the situation today and can you explain it with a bit of historical context for naive readers like me? Thanks!" asked milkmilk_lemonade.
Robertson: "Historically, decades back, the border between Saudi Arabia and Yemen was very open -- little more than a line on the map. If you go back before that, there was not even a line on the map.
More recently, about 6 years ago, Houthi tribesmen crossed in Saudi took control of a village. There was a three-week battle with helicopter gunships before Saudis got it back. As Yemen has become more unstable, its economy has gotten worse.
Clearly, Saudi Arabia is the richer country with more oil, so the border is division between the haves and the have-nots on Yemen side. So many come to Saudi Arabia for work, even an 11-year-old boy I met who earns $100 a month working on a till at a small supermarket. It's the only way for some Yemenis to make money, so they cross over for stays that last weeks or months. The huge numbers crossing make it hard to control and know who is who --terrorist or poor guy."
Q: "Is there anything from the border you want to share, that wasn't included in the story? Can you talk about the process and problems of trying to gain permission for it?" asked sirpoopsal0t.
Robertson: "There were so many more people than we could get in our TV reporting. I wrote a story for CNN Digital after I did the TV piece to cram in more details, but I was shocked. I didn't quite know what to expect that day, but it was way more people and drugs than I'd realized. We try to get everything in our reports, but we saw group after group being caught, particularly at dusk."
Q: "How was my country's border patrol/army? Were they as you expected? Worse maybe?" asked sai911.
Robertson: "They were professionals. I was struck by the quality of the officers and the access we were given. I was only there for a day, but they have a huge job on their hands."
Q: "What have you found to be the biggest three obstacles in locating terrorists?" asked DebraLynnO.
Robertson: "They can usually be found through intermediaries, but sometimes it's more dangerous than others."
Q: "Hi Nic. It takes [nerve] to do what you're doing! Why are you doing it? What made it happen?"
Robertson: "It's important that the world hears what's happening in its darkest corners. It's important for the people in those dark places to know that people care, that they are people too and that their lives count."
Q: "When traveling in dangerous countries does the fear ever leave? Do you get an opportunity to meet people and enjoy their way of life?"
Robertson: "Yes, on the good days we do get time to meet folks. At the end of the day on the border we had half an hour to spare and the border guards took us to the beach and gave us dinner -- fish, lamb,.. salads, humus, bread -- right there on a rug at the beach. We got to relax a little before we ran off to catch the plane. Sometimes after an interview, we can chill out a little with folks in their homes. Those can be interesting conversations.
"We always have mind to dangers of any location."
Q: "You always hear about post-traumatic stress disorder with soldiers. Do you find yourself experiencing it given your work?" asked allianceofmagicians.
Robertson: "Sure, PTSD does hit journalists too. Soldiers tend to face the exposure to those kind of traumatic events for much longer and often more intensely than we do. We have access to help here at CNN and I've talked to our expert over the years.
"I've never felt that I've suffered from PTSD, but I'd say I do get awfully sad sometimes after a bad story -- tears, etc. -- but it passes. I have a great home life, I love to run and cycle. That kind of stuff gets you out of yourself, but I'd say my exposure to trauma has not been that excessive."
Q: "CNN keeps reminding us at home that they aren't going to show any of the photos of the captured Jordanian pilot. During and after the Charlie Hebdo massacre they kept letting us how they weren't going to show any of the offending cartoons. With all you've seen what are your thoughts on news organizations making those kinds of decisions?" asked Mutt1223.
Robertson: "In this day and age all these things can be found online someplace. At least that's my experience. I have seen the video of the pilot, and I feel horrible.
"The Pope posed an interesting question about what sort of people do we want to be. The power is in our hands. Do we want to inflame or do we seek a more just, equitable world where we respect and tolerate each other
. Its a powerful concept."