Former U.S. Defense Secretary William J. Perry is warning the world of a "real and growing danger" of nuclear annihilation. Perry, 88, says he worries that terrorists could nuke the United States "any time now - next year or the year after" - or that a miscalculation could cause a shooting war with Russia to quickly turn nuclear, reports The Associated Press.

"We are facing nuclear dangers today that are in fact more likely to erupt into a nuclear conflict than during the Cold War," Perry said in a recent speech.

The three-time senior Pentagon executive, originally a mathematician before entering the defense world in the mid-1950s, helped overlook the development and modernization of the U.S.'s nuclear arsenal during the Cold War.

In his newly published memoir, "My Journey at the Nuclear Brink," Perry recounts how he was secretly asked to come to Washington and analyze intelligence about Soviet weapons in Cuba.

"Every day that I went to the analysis center I thought would be my last day on Earth," he writes, chalking up humanity's avoidance of a nuclear holocaust to pure luck.

One morning at 3:00 a.m., Perry and other officials were warned that 200 nuclear-armed missiles were on their way from the Soviet Union, as described by George Washingotn University's National Security Archive. It ended up being a false alarm, but Perry said such incidents gave him a "unique and chilling vantage point from which to conclude that nuclear weapons no longer provide for our security - they now endanger it."

He has called for the dismantling of the U.S.'s land-based intercontinental ballistic missiles, or ICBMs, saying that the military can rely on bomber aircraft and submarine-based missiles instead. "I don't think it's going to happen, but I think it should happen. They're not needed" to ward off nuclear aggression, he said, according to AP.

Perry has also spoken out against President Obama's plan to spend $1 trillion on upgrading the nuclear arsenal over the next three decades, including spending at least $20 billion on 1,100 new nuclear-armed cruise missiles, according to U.S. News & World Report.

"I see an imperative to stop this damn nuclear race before it gets under way again, not just for the cost but for the danger it puts all of us in," Perry said.

"Our chief peril is that the poised nuclear doom, much of it hidden beneath the seas and in remote badlands, is too far out of the public consciousness," he writes in his memoir. "The danger of a nuclear bomb being detonated in one of our cities is all too real. And yet, while this catastrophe would result in a hundred times the casualties of 9/11, it is only dimly perceived by the public and not well understood."