CIA insider on Australia hostage crisis: "ISIS sees them as an enemy"

It's still unclear what motivated Iranian-born Man Haron Monis to allegedly take hostages in a café in downtown Sydney, Australia. Monis died after police raided the Lindt Chocolat Cafe, ending the 16-hour standoff. Two of the hostages died as well.

Monis, identified by police as a local Muslim cleric, appeared to be supporting the Islamic State of Iraq and Syria (ISIS). According to CBS News partner Ten Eyewitness News, the gunman made two demands: to have an ISIS flag delivered to the cafe and speak to the Prime Minster Tony Abbott.

"There's really a couple of possibilities here," CBS Senior security contributor Mike Morell said on "CBS This Morning." "One is that this person has been directed by ISIS to do this. Second is that this person went to fight in Syria and has now come back. The third possibility is that this person has just been self-radicalized by the ISIS message. The fourth possibility is that he's mentally ill."

Morell said ISIS has been focused on Australia for some time now, with about 300 Australians having traveled to the Middle East to fight -- 70 or so for ISIS. In September, Australian officials thwarted an alleged terror plot and arrested several people after a senior ISIS leader called for individuals to behead Australians in public.

The raids in September came days after Australia raised its terrorism threat to the second-highest level.

"Australia is seen by groups like ISIS as a partner of the West, which it certainly is," Morell said. "Australia was a coalition partner in the war in Iraq, a coalition partner in the war in Afghanistan and is now a coalition partner in the fight against ISIS. So ISIS sees them as an enemy."

As ISIS gains more publicity around the world, worries are mounting of their growing success in encouraging lone wolves to carry out these types of attacks.

"What concerns me the most is that we're going to see this kind of terrorism around the world, and we are going to see it here," Morell said. "It shouldn't surprise people when this happens here sometime over the next year or so, guaranteed."

But Morell said unless officials are able to pick up information on suspected plots, it's very difficult to stop attacks planned under the radar.

"One way this happens is if ISIS leadership directs it, and intelligence agencies can often see that and prevent it," he said. "If people are vocal on social media about what they're going to do, you can often prevent it. But if they're quiet about it, it's easy to carry out something like this, very difficult to prevent it."