Should the U.S. be forced to engage an inbound North Korean ICBM with missile defense systems, that engagement could occur over Russian territory, which of course further complicates things.

If Pyongyang fires a missile at the United States, its most-likely trajectory would take it over the North Pole. A U.S. attempt to shoot down that missile would probably occur within Russian radar space — and possibly over Russia itself.

“It’s something we’re aware of,” Gen. Lori Robinson, who leads both U.S. Northern Command and the North American Aerospace Defense Command, or NORAD, said Wednesday. “It’s something we work our way through.”

By year’s end, the U.S. will have deployed 44 ground-based interceptors, or GBIs: 40 at Fort Greeley, Alaska, and four at Vandenberg Air Force Base, California. If deterrence fails, those interceptors would be the last line of defense against a North Korean missile. Each incoming ICBM might be met with four or more GBIs.

Last week, Joshua Pollack told an audience at the annual Air Force Association conference in Washington D.C. that the most probable intercept route aims the U.S. GBI “into the teeth of the Russian early warning net.”

There are other possibilities as well. Some experts believe it might be better to wait until the missile is on its downward trajectory because it will be slower and more easily engaged.

As for Gen. Robinson, she laid out in general terms what engagement might look like. “What you have to do is sit down and go, okay, what is the azimuth” — the direction of the object in the air from the perspective of the observer. The next question, she said, is: “When would be the right time to take the best shot to defend? That’s about all I’ll say.”

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