A Brock University operations research associate professor says when an anti-ship cruise missile sank a navy warship for the first time ever 50 years ago, it was a turning point for international conflict.

Associate Professor Michael Armstrong, who uses mathematical models to study missile combat at sea and short-range rocket defenses on land, said the sinking of the Israeli destroyer INS Eilat on Oct. 21, 1967 “opened the eyes of navies around the world.”

Armstrong, Associate Professor of operations research in the Goodman School of Business, said that event forced the development of missile defence systems, which are back in the news these days with the growing tension between the U.S. and North Korea.

“It’s much more on people’s minds,” said Armstrong, who authored an article on the issue recently in The Conversation Canada.

In the years since the INS Eilat was destroyed, Armstrong said there have only been two cases of warships using interceptor missiles to down hostile cruise missiles coming at them. One came in 1991 when Britain’s HMS Gloucester shot down an Iraqi cruise missile, and then in October 2016, the USS Mason defended itself from attacking cruise missiles while patrolling the Red Sea.

While the concept of missile defence from the sea or on land is essentially the same — “you have this incoming missile and you try to shoot it down with a missile,” Armstrong says — actually shooting down a ballistic missile like the ones being tested in North Korea is more complicated.

“On a ship, the challenge is to detect that missile. Once you pick it up on radar, it’s relatively easy to shoot down. It’s also relatively easy to distract and fool the incoming missile,” he says.

Ballistic missiles, on the other hand, are easy to see because they show up on radar systems around the world.

“But they’re harder to hit because they’re flying over 10 times faster. They’re way up in the sky,” Armstrong says.

And unlike a cruise missile that would simply crash into the sea if it’s damaged by a defence system, it’s not enough to just damage a ballistic missile because it could still end up crashing down over a populated area.

So is North America ready if a ballistic missile is fired in its direction?

“Nobody really knows,” Armstrong says. “This comes back to the naval context. The one system that is considered most reliable or has the best chance is the technology that’s based off the naval system.”