Sydney hostage crisis highlights lone wolf threat in U.S.

U.S. law enforcement is on alert following Monday's deadly hostage crisis at a coffee shop in Sydney, Australia. Police there were eventually able to take control of the situation, but officials are warning a similar lone wolf attack could easily happen in America.

"I think it's less a question of if, more a question of when," NYPD Deputy Commissioner of Intelligence and Counterterrorism John Miller said Tuesday on "CBS This Morning."

"You have to go back to September, when ISIS put out the call through its official spokesman for people to attack in their own countries with what they have at hand," said Miller, a former CBS News correspondent.

He cited a series of attacks in October, including one by Martin Rouleau, who ran over two Canadian soldiers, the attack on the Canadian parliament by Michael Joseph Zehaf-Bibeau and the assault on NYPD officers with a hatchet. It's events like those, where attackers may have been inspired by ISIS that has led Britain and Australia to increase their terror threat level.

In New York City, Miller said preparations for those possible incidents have been in the works for 13 years.

"We have a distinct advantage in that there are a thousand people in the NYPD who work counterterrorism matters on a daily basis," Miller said. "There's 400 people in the emergency service unit, which would be the equivalent of our SWAT team, so if you take a small scenario at one location as we saw in Sydney, or a wider cast like the Mumbai attacks, we're one of the few cities that is scaled to meet that."

While he couldn't share specific information on what U.S. officials took away from the siege, for safety reasons, Miller confirmed he spoke to Sydney Police Comissioner Andrew Scipione and discussed their tactical considerations. He did share how the NYPD prepared their resources in the event a simultaneous attack was planned in New York.

"All the time that this is going in, you're asking yourself and your partners in Sydney, do we have any idea of the clear motivation, why this place, why this target, why these tactics? And you're saying if you take the New York overlay, how do you apply protection there?" he said. "So additional resources were dispatched to the Financial District, to Columbus Circle, to key Australian locations, and some of that we'll tamp down now that was have an understanding of what this was and who this suspect was."

But while Miller praised the New South Wales Policem saying, "I don't think you could have done better or achieved a better outcome, tactically," some wonder why Man Haron Monis wasn't killed earlier in the standoff, pointing to images where he could be plainly seen in the café window. Miller said there were tactical reasons for not carrying out such action.

"One might be that when you have an individual who has a backpack that he says has four kilos of explosives on it, there are a number of possibilities. One is a dead man's switch, which is if you shoot him and he falls down, it'll detonate a device that could kill everybody in that place. But also in that area, a number of the places were asked by the police to harden their targets because they knew it was a potential place for a terrorist attack. So many of them, including this location, have reinforced glass which would be resistant to a sniper's bullet."

Miller also pointed out the unique challenge of terminating a terrorist hostage situation, which he said is distinct from a criminal hostage case.

"In a criminal hostage situation, you have somebody who didn't intend to take hostages, they just got surrounded by the police while they were robbing the bank. Their motive is, how do I get out and how do I get the best deal," he said. "When you have a terrorist hostage situation, you have a couple of other things, which is often times they go in not intending to get out alive and they don't care, nor do they intend to get everybody else out alive."

The key though, is to stop these attacks before they occur, tracking lone wolves as they travel and determine if they're fighting for a specific terrorist organization.

"Both the FBI on a national basis [and] the National Counterterrorism Center have done a very good job at tracking people who are being recruited by ISIS, being recruited by al Nusra ... and either stopping them on the way out or intercepting them on the way back."