Photo: The Canadian Press

Decommissioned Nike missile control site in California.

After the Soviet Union collapsed in 1991, the era of nuclear nightmares — of the atomic arms race, of backyard bomb shelters, of schoolchildren diving under desks to practise their survival skills in the event of an attack — seemed to finally, thankfully, fade into history. Until now.

For some baby boomers, North Korea's nuclear advances and President Donald Trump's response have prompted flashbacks to a time when they were young, and when they prayed each night that they might awaken the next morning. For their children, the North Korean crisis is a taste of what the Cold War was like.

"I'm not concerned to where I can't sleep at night. But it certainly raises alarms for Guam or even Hawaii, where it might be a real threat," said 24-year-old banker Christian Zwicky of San Bernardino, Calif.

People of his parents' generation were taught to duck and cover when the bombs came. "Maybe those types of drills should come back," Zwicky said.

Retiree Scott Paul, 65, of Los Angeles said even as a 10-year-old, he wondered how much good ducking under a desk could do if a bomb powerful enough to destroy a city fell nearby. No good at all, his teacher acknowledged.

Then there were backyard bomb shelters, which briefly became the rage during the missile crisis of 1962, when it was learned the Soviets had slipped nuclear-tipped missiles into Cuba and pointed them at the United States. After a tense, two-week standoff between President John F. Kennedy and Soviet leader Nikita Khrushchev that some believe brought the world the closest it's ever come to nuclear war, the missiles were removed and the shelters faded from public interest.

Now they, too, seem to be having a revival.

"When Trump took office it doubled our sales, and then when he started making crazy statements we got a lot more orders," says Walton McCarthy of Norad Shelter Systems LLC of Garland, Texas. "Between now and a year ago, we've quadrupled our sales."