Host Tyler Mathisen: Authorities in Australia staging the largest counterterrorism operation in the country's history Thursday to disrupt a gruesome plan by Islamic militants living in the country to carry out random public executions or demonstration killings. Australian media reporting the suspects wanted to kidnap and behead a member of the public and drape the body in an ISIA flag. Australia just the latest example of radicalized Islamic militants waging terror from within on the home front. We've already seen murderous attacks in Belgium and England. Steve Emerson is an author and executive director of the Investigative Project on Terrorism and Ghaffar Hussain is a director at Quilliam, a counterterrorism think tank in London. Welcome to both of you. Mr. Hussein, let me begin with you. How close a call was this?

Ghaffar Hussain: From what I'm hearing, it was pretty close. The Australian police intercepted a phone call which suggested that these individuals, or one individual is a quite high-ranking member of ISIS, and he had been given instructions to now carry out this attack in response to, or as a tactical response from the ISIS point of view to the fact that the Australians are now sending troops to the region to help in the international effort to defeat isis. So I suppose we're starting to see a number of things ISIS doing now, all of which are aimed to kind of prevent or the international coalition which has been a real game changer in holding back ISIS in Iraq.

Mathisen: Mr. Emerson, react to what Mr. Hussain just said, but also put in context the idea that the biggest terror threats may now come from within, not from without, and who are these people? Are they nationals of Australia or people who have gotten in via a passport? What?

Steve Emerson: Well after 9/11, the biggest threat was from al Qaeda [was] sending in operatives or trying to remotely detonate planes through operational devices that could remain undetected. Then we went through a period of homegrown terrorists who weren't directed by al Qaeda but were recruited online or by the Muslim leaders in their own community. Now we're into jihad 3.0 where we have people who are volunteering to battle Syria or the West in Iraq and in Syria, gaining the incredible experience of fighting, and then possibly returning back to their own countries in Europe, Australia or the United States. Now you have to remember that the people who are being recruited get vetted before they go to Turkey, which is the infiltration route. Then they get vetted at the border between Turkey and Syria to see who is willing to die and who is willing to be the most vicious. So when they return back to their home countries, you already have a preselected number of jihadis who are willing to die or carry out vicious acts of violence like beheadings. We haven't experienced that in the US yet, but it certainly has been experienced in Belgium, Germany. It's been experienced in Britain and now in Australia.

Mathisen: Mr. Hussain, how easy or difficult is it to track these individuals who as Mr. Emerson just described have a rather circuitous path, often moving through Turkey into Syria, into Iraq? How easy is it to track them so that when they try to come back into the United States or Great Britain, they can be identified, detained, investigated?

Hussain: Well, it's not straightforward to stop people going or people returning. Turkey is a very popular holiday destination for many British people. And millions go there every year. It's very easy to get a cheap, low-budget flight to Turkey and then get a coach across to the border and cross over. And if someone's done that for a few weeks or even longer and decides to come back, unless they've popped up on social media and talked openly about what they've been doing, we're not going to really know what they've been doing, these individuals. So it is very worrying that it is quite easy, in my opinion, to get back into Europe, certainly Britain or America, certainly very easy to get back into Europe, European territory, from Turkey and from Syria. And part of the problem is the fact that the Turkish government has actually turned a blind eye to these individuals because they have their own tactical objectives of overthrowing the Assad regime. And in the past they have not done enough to secure that border. So many individuals are getting the know-how, getting the motivation from individuals they come across online and then arranging to meet them at the Syrian border so they can go over and join ISIS.

Mathisen: We're very tight on time. Mr. Hussain, thank you very much. Steve Emerson, where is the risk most prevalent and what would you expect the next sort of terror target to be? Would it be those kinds of streetnappings, or would it be the kind of attack that we saw in the shopping mall in Nairobi about a year ago? Very quickly.

Emerson: I think it would be the latter. I think we're probably going to see--[although] it's impossible to predict, a freelance--a homegrown terrorist returning from Iraq or Syria who decides to detonate a bomb someplace remotely or carry out a suicide bombing on his own like we saw in Belgium and in France in the last two years.

Mathisen: Is Europe more vulnerable than the United States, or can you tell?

Emerson: Europe is more vulnerable because there are ten times more numbers of jihadi volunteers, up to 5,000, who have gone over to Iraq and Syria. In the United States, only about 200 to 300 have. But that number is growing, unfortunately.

Mathisen: Gentlemen, we thank you both for your perspectives on this very chilling topic.