Air Force Gen. Terrence J. O'Shaughnessy, commander of North American Aerospace Defense Command (NORAD) and Northcom, noted that care must be taken not to let potential adversaries take advantage of that cooperation.

These remarks come after the commander noted that the Russian Navy has been deploying warships with cruise missiles on Arctic lanes, along with regular military aircraft patrols above the North Pole and "up to the edge of US and Canadian airspace."

As avenues of navigation open in the Arctic region, so to do avenues of approach to the United States, O'Shaughnessy noted, so the US, and Northcom in particular, must remain vigilant and prepared.

The Arctic is not just a place you can pick up and go to,

...he said.

Unlike the tropical, temperate or desert environments where the US military typically operates, the Arctic region requires specialized training and gear.

Turning to missile defense, O'Shaughnessy said defense against cruise missiles is something that needs more attention.

He noted that discussion of ballistic missile defense is common, and the US spends as much as $12 billion a year on ballistic missile defense. There's also growing discussion on defense against hypersonic weapons, he said.

But surprisingly, there is not that much conversation about cruise missiles. When I look at the cruise missile threat, I see that as one of the biggest threats we face,

...he told the audience.