The Canadians stay in the room. They keep working.
The idea that Canadians are forced to leave during the missile-defence system's tests and false alarms is one of many myths swirling around the program, which generated noisy debate a decade ago in Ottawa and could soon do so again.
The reality is that Canadians work a few metres from U.S. missile-defence officers. There are dozens of desks in the room, and the missile officers occupy a couple near the middle. Everyone's seated under a row of giant-screen TVs showing satellite images and the popular U.S. news channels, with a big motivational banner above that says, "We Have the Watch."
This places Canadians well within earshot of their American colleagues in the command centre at Peterson Air Force Base, Colo., home to both the Canada-U.S. North American Aerospace Defence Command and to U.S. Northcom, the American military unit that oversees the missile system.
The Canadians wouldn't have a role in deciding when, where or whether to launch against an incoming object. But they'd keep feeding data from the tracking system to their American colleagues, seated beside them.
"I can't think of a single moment where Canadians wouldn't be involved," said U.S. Col. Steve Sicinski, during a tour of the command centre. "They're there all the time."
The process would unfold within minutes.
Because Canada refused to join the program in 2005, the call on pulling the trigger would run exclusively through the American chain of command and ultimately fall with U.S. Gen. Charles Jacoby, who heads both Norad and Northcom. One official said Jacoby could be in that command centre — or perhaps in his office elsewhere on the base, or even at the grocery store — while talking to Washington about a response.
As for Ottawa's role, a pair of parliamentary committees have been studying the program and the Harper government hasn't ruled out joining. Should Canada join, the U.S. military says the system could use new sensors in the Arctic — multi-use devices that would track ships, planes, and long- and short-range missiles.
Here are other facts about the U.S. missile program:
—It's not based in a mountain nuclear bunker. Norad was based in Cheyenne Mountain for decades, but relocated in 2006 to the base near the Colorado Springs airport. There are myriad checkpoints, metal detectors and an ID check through a one-way mirror before base personnel can access the command centre shared by Norad and the missile program.
Canadians occupy desks throughout the room — except for the pair of seats for the U.S. missile-defence officers, and a group of desks in the back that belong to U.S. intelligence officers.
—Star Wars? Not quite. There have been different visions for a U.S. missile system, dating back half a century. One, proposed by Ronald Reagan under the name Strategic Defense Initiative, got the sci-fi nickname as it called for anti-missile lasers in space.
The program now tracks objects through sensors in space, at sea and on different continents. Finally, there are 30 interceptor rockets in Alaska and California. They can launch 68-kg "kill vehicles," designed to obliterate a missile as it descends. The collision speed occurs at 59,000 kms per hour.
U.S. Brig-Gen. Matt Molloy, who oversees the program under Jacoby, calls it a "bullet hitting a bullet."
—The system just passed a test — finally. The program hadn't had a successful test in six years, failing six of its last nine. These failures occurred in an extremely favourable environment — without decoys, simultaneous attacks, or the element of surprise.
But on June 22, the system smashed a missile out of the sky over the Pacific Ocean.
"It was gone. Vaporized. Done," Molloy says.
—It's pricey. The U.S. has spent about US$100 billion on the program since 2002, and it plans to spend $8 billion more each year — about two per cent of the entire U.S. military budget, says a study by the Council on Foreign Relations.
Molloy calls the system a national treasure: "How do you put a price on 120,000 souls in Seattle? Are you kidding?"
—It's not designed to scare off big countries, like the Reagan-era program. The current version is supposedly for knocking down an attack by a rogue state. The one most often mentioned is North Korea.