(Inside Science) -- Earlier this month, North Korea threatened to retaliate with nuclear weapons if the U.S. or South Korea "fire even a single bullet" at the sovereign state. While this seemingly extreme statement fits the mainstream narrative of a paranoid regime, some experts hold a different view.
"When people talk about nuclear weapons, we always have this idea [that] only a delusional, irrational, crazy leader would actually use them, when in fact from a rational standpoint it makes total sense for a weaker adversary to use [the threat of] nuclear weapons to escalate a conflict in order to create a stalemate," said Keir Lieber, an expert on nuclear weapons and international relations at Georgetown University in Washington, D.C.
The brinksmanship is further complicated by changing technology. In response to nuclear threats from North Korea, the United States and its allies are developing new "counterforce" capabilities, which could destroy an adversary's weapons before they have a chance to use them. But some experts warn the new technology could upset the precarious balance of power, and lead to a new arms race.
Our guardian angels in space
"Nuclear forces are becoming more and more vulnerable to pre-emptive attacks, to counterforce," said Lieber. He recently presented the topic at a meeting of the American Physical Society, in New Orleans, and will publish a new analysis of the trend in an upcoming issue of the journal International Security.
With today's advanced satellite technologies, it is now more difficult for nations to protect or hide their nuclear arsenals. For instance, the accuracy of missile guidance systems has improved drastically since the last century. GPS -- which is used in some missile guidance systems -- has evolved from an accuracy of several miles during the 1970s to within an inch today.
With these improved technologies, today's missiles can reliably deal a direct hit to a hardened target such as a fortified underground silo. For example, according to a specific case study in Lieber's upcoming publication, current submarine-launched ballistic missiles have an 80 percent success rate in destroying a hardened target such as a concrete bunker, compared to less than 10 percent in 1985.
As for remote sensing, many modern satellites are equipped with multispectral or hyperspectral imaging capability. These imaging techniques, as their names suggest, take pictures over a wide range of wavelengths of visible and invisible light. Just like how a hunter can better spot a deer in the woods with an infrared camera, a satellite with multispectral imaging capability can detect trucks or concrete bunkers hidden in the forest based on the unique spectral signatures of each material.
Just this year the U.S. military performed another successful launch of a series of satellites designed for missile defense purposes, with better locating and remote sensing abilities than its predecessors. At least one more satellite is already planned for launch within the year, with at least two more in the works. With more satellites in the sky, there are fewer places to hide weapons and the structures that house them.
In theory, the U.S. military could use what they find to target and destroy weapons systems in North Korea. However, even with the impressive scope of these new technologies, some experts remain skeptical about their ability to significantly impact missile defense in reality -- in particular against a first strike attack. For instance, if North Korea launches multiple intercontinental ballistic missiles against its adversaries today, the U.S. missile defense systems still probably cannot intercept them all, even with today's cutting-edge technology.
"Can we integrate all of this information with very high reliability, and get that information to the people who need it in a timely fashion for them to act on it? " said Jeffery Lewis, the Director of the East Asia Non-Proliferation Program at the James Martin Center for Nonproliferation Studies in Monterey, California, referring to the information collected by the surveillance satellites. "The data is huge, and that's just one of the challenges."
A new kind of arms race
There is a saying among nuclear strategists, Lieber said, which captures the field's sometimes counterintuitive logic: "Killing people is good, killing weapons is bad." That is to say, the threat of mutual assured destruction can provide a stable stalemate, while technological advancements in counterforce capabilities can actually provide renewed incentives for an arms race. If a nation's nuclear arsenal becomes more vulnerable to attack, its leaders may decide to stockpile more weapons and locate them in more areas throughout the country, for example.
"Whatever the technology the United States develops, the North Koreans will have their own countermeasures," Lewis said. "They're not idiots."
So, as necessary as it seems for the United States to defend itself against North Korea's nuclear threats, counterforce measures may actually destabilize an ongoing conflict and trigger an arms race.
"We tend to dismiss North Korea's scientific and industrial capabilities, and are continuously surprised by each new development. I think we have erred in downplaying what they can do," said Joshua Pollack, the editor of the Nonproliferation Review. "Simply because their civilian economy is weak, does not mean their military economy is weak as well."
Is détente possible?
Given the mistrust that exists between rival nations, experts are split on what, if anything, should be done to best stabilize the situation.
North Korea joined the Nuclear Nonproliferation Treaty in 1985, but then in 2003 became the first nation ever to withdraw from the agreement. They successfully tested their first nuclear bomb October 9, 2006. Five more tests soon followed. They are now claiming to be in the "last stages" of developing an intercontinental ballistic missile capable of reaching much of the United States.
According to Pollack, the North Korean regime would point to Libya, and link that nation's nuclear disarmament in 2003 to the ultimate downfall and violent death of its leader Muammar Gaddafi. "They are determined never to surrender their nuclear capabilities because they see it as the key to their survival," Pollack said.
The U.S. also seems unlikely to back down. In a December tweet, then U.S. President-elect Donald Trump wrote, "The United States must greatly strengthen and expand its nuclear capability until such time as the world comes to its senses regarding nukes." On March 17, U.S. Secretary of State Rex Tillerson told a news conference in South Korea that "all of the options are on the table," regarding the use of military force against North Korea.
But "there is no winning last move in an arms race," said Pollack. "All you can do with your nuclear weapons ultimately is threaten your enemies and all they can do is threaten you, so you actually have a shared interest in managing and reducing that threat."
"That's the logic anyway," Pollack added.