Transcript for Lt. Col. John Nagl: 'There Are Not Enough Troops Right Now'
And Martha joins us now along with two former officers. Doug oliphant and John nagl. And Martha, incredible report there, we just heard general Campbell say everyone wants us there, but are there enough troops for the mission they have been given? One of the hidden costs there are the contractors. It's a three to one difference. 9800 U.S. Troops. You have about 30,000 contractors and most of them are U.S. And most of them are doing jobs out in the field around, backing up those troops wherever they can. I asked general Campbell, do you have enough U.S. Troops? Obviously, any commander is going to tell you, he probably wants more. But they're getting by with those 9800. He says the Afghan forces are doing a lot better. He says that he's a glass half-full kind of guy. Afghan forces still have a long way to go. George, basely, what they're in right now is a reactive mode. The Taliban has changed its strategy. It's going into cities. The Afghan forces have to go to those cities and leave other areas like the south. So, colonel nagl, is the glass half-full, are there enough troops? There are not enough troops right now. The president has finally decided to keep 5,000 troops in Afghanistan over the course of the rest of his presidency, but the fact is, the U.S. Has enduring national security interests in Afghanistan and Pakistan, that will remain the case for decades to come. And I think the right thing to think about, in South Korea, 30,000 troops for 65 years, I predict the next president will triple the number of troops in Afghanistan and they'll be there for decades. Triple the number of troops. We're hearing this metaphor a lot now, it does violence to this situation. South Korea is not Afghanistan, in South Korea after the Korean war, we put troops there to essentially maintain the status quo and they sat there to make sure that the north Koreans didn't come and invade the place. Afghanistan is different. It's in the middle of a civil war, and we need to transform that place. It's a landlocked country, it doesn't have a lot of product to export except for opium. It seems unlikely that we're going to fundamentally transform this place. At incredible costs as Martha pointed out. The back of the envelope math we use, $1 million, $2 million per year per soldier. Largely because there are three contractors for every one soldier. Already 14 years in, Martha you said the Afghan troops are doing better, are they ever going to be strong enough to go it alone? Certainly not for a long time. The Afghans really don't have that. Their air force is very, very tiny. So, I think it will take a long time. One thing that we haven't mentioned is Iraq. That's one of the lessons here that the president relied on, pulling out all troops in Iraq, look what happened. He doesn't want that to happen. There are going to be more AIDS like the one we saw in Iraq. Colonel nagl, do you think the American people are prepared for that kind of commitment we'll need to make in Iraq and Afghanistan? I absolutely do. We have an all-volunteer force. American soldiers are willing to continue to fight against the islamic state both in Iraq and Afghanistan in order to keep the homeland safe. And that's probably the biggest difference between the American commitment to South Korea and the enduring American commitment to Afghanistan and Iraq, there are still threats to the homeland from Iraq and Afghanistan. Colonel ollivant, what would you say to someone about the military situation isn't all that different since president Obama took office? It certainly appears that way, certainly in Afghanistan, doing a quick read of the last few days' papers, the road between kabul and kandahar is cut by the Taliban. That would be like someone cutting I-95 between Washington, D.C., and New York. Clearly, the Taliban is on the move in Afghanistan. I think John is right that there are not enough troops there to keep that from happening. The question is, do we want to spend $20 billion, $30 billion, $40 billion a year for as long as the eye can see? You know that's real money, even by government standards. Do we have that much national interest in Afghanistan? And for that matter, is the threat to the homeland from Afghanistan any higher from Libya, Syria? If I were a terrorist, I would put my base camp in one of those countries, much closer to Europe, much closer to America. This will be a big issue. It's quieted it down a little bit because the president left troops there. But honestly, George, I don't think Americans are ready for what's happening on the ground in these places. If it keeps happening and we keep losing Americans in the fight. Thank you all very much. Up next, Ben Carson stirs up controversy, surges in the polls, his challenge to trump. And Jeb bush's drastic moves. That's all on our roundtable. Announcer: Catch "This week" online all week at abcnews.com. On Facebook and Twitter.
This transcript has been automatically generated and may not be 100% accurate.