The US can survive a nuclear North Korea - but a first strike could start World War III
But a nuclear armed North Korea wouldn't be the end of the world, according to some senior military officials.
"We can deter them," Adm. Dennis Blair, the former head of US Pacific Command, said of North Korea at a National Committee for US-China Relations event. "They may be developing 10 to 15 nuclear weapons. We have 2,000. They can do a lot of damage to the US, but there won't be any North Korea left in the event of a nuclear exchange. That's not a good regime survival strategy and even Kim Jong Un would understand that."
The US has to live with the fact that Russia, the world's second greatest nuclear power, openly opposes the US's foreign policy in nearly every dimension. And it lives with the fact that Pakistan, a country rife with corruption and Islamist groups gaining traction within and around their borders, has nuclear weapons.
A senior Defense Department official with expertise in nuclear strategy told Business Insider that while the US says it cannot and will not accept a North Korea armed with a nuclear intercontinental ballistic missile, that amounts more to an opening position in an ongoing negotiation than an intention to use military force in order to stop it.
"You never undermine your official position going in," the official told Business Insider. "You're never going to voluntarily back away from that. You're going to actively work to make sure they don't get" an ICBM.
"The North Koreans having nukes is a bad thing and we don't want it. But if we lose that one, we survive it," the official said.
Despite bluster on both sides, whether it's posturing that the US may attack to cripple North Korea's nuclear program, or that North Korea would use its nuclear weapons on the US or allies, the defense official and other experts contacted by Business Insider found both cases extremely unlikely and undesirable.
"That's because there's no good thing to do. They have to convince South Korean allies and North Korean adversaries that they'll do anything to protect Seoul, even all out nuclear war."
"But those experienced military leaders know, they've run the models, they've run the numbers," said Hanham. There's just no way to fight North Korea "without chaos and enormous death and damage to the world."
Because US nuclear weapons would have to overfly China or Russia, and would likely spread deadly fallout into South Korea or even as far as Japan, it's likely that nuclear conflict with North Korea would bring about World War III - the great power war between nuclear states that the world has developed nuclear weapons to avoid.
To an extent, the US already lives with and deters a nuclear North Korea on a daily basis. Hanham said that although it hasn't been verified, North Korea most likely has a deliverable nuclear weapon that could hit the 10 million civilians in Seoul or the 25,000 permanent US troops stationed in South Korea.
So North Korea will continue on its path towards a nuclear weapon that can hit anywhere in the US, but like Russia, China, and Pakistan - they probably won't.
This is an opinion column. The thoughts expressed are those of the author.