Dozens upon dozens of missiles take flight.

For years, the world had heard warnings, but most doubted the day would ever come. Most missiles fall before allied defenses, but one finds its mark — it’s the one that matters most. In a flash, hundreds of thousands, if not millions of people perish.

Would North Korea fire off a nuclear weapon? No one knows for certain, but what we do know is that the above scenario is exactly what an aggressive and increasingly-powerful North Korea has been threatening for decades. While the reclusive regime may have previously lacked the necessary weaponry, the North now has the kind of capabilities to turn at least some of its threats into promises.

The U.S. and its East Asian allies have strategic defense assets in position, but war is full of uncertainties. “People think missile defenses are a magic wand. They aren’t,” Jeffrey Lewis, a renowned arms expert, told The Daily Caller News Foundation (TheDCNF).

Here’s what happens if the North pulls the trigger.

What Would Happen If A Launch Appeared Imminent?

The U.S. and its allies in the region are by no means unprepared for a North Korean nuclear attack.

The U.S. and South Korea both have preemptive strike plans for a situation in which a North Korean nuclear attack appears imminent, and while Japan is considering new options, it still relies heavily on U.S. defense.

South Korea has a three-stage defense system, the first stage of which is a preemptive strike option designed to eliminate the North’s offensive capabilities. The “Kill Chain” preemptive strike system detects signs of an impending nuclear missile launch and strikes the North’s nuclear weapons sites and missile bases with cruise missiles and other weaponry.

The U.S. and South Korea also have a joint response plan, Operations Plan (OPLAN) 5015.

While the specifics for OPLAN 5015 are classified, the plan is believed to consolidate previous contingency plans, specifically OPLAN 5029 (internal instability in North Korea), OPLAN 5027 (preparations for an all-out war), and a peacetime plan involving localized provocations from North Korea. OPLAN 5015 is suspected to call for preemptive strikes on the North’s essential military facilities and weapons, and possibly North Korean leadership.

In the event that a nuclear missile strike appeared imminent, allied forces might attempt to eliminate the North’s missiles at launch. Mike Mullen, the former chairman of the Joint Chiefs of Staff, said last year that the U.S. could move to “take out launch capabilities on the launchpad” if North Korea appeared poised to launch a nuclear armed-missile.

The U.S. and South Korea regularly train for such contingencies. For example, during the annual Key Resolve and Foal Eagle exercises, U.S. and South Korean troops practice a “4D” operational plan which involves preemptive military options to detect, disrupt, destroy, and defend against North Korean strikes. The focus is precision strikes on the enemy’s core military facilities and weapons systems.

The challenge is that more and more of North Korea’s missiles are on mobile launchers and scattered about the country. Furthermore, the Korean People’s Army (KPA) has started using solid-fueled missiles, which require significantly less preparation time as they can be fueled in advance and need only a limited crew. Solid-fueled missiles can be fired with less warning and are much harder to track, making them less vulnerable to preemptive strikes.

Another issue is that preemptive strikes on North Korea would be much harder to justify diplomatically, especially if war breaks out in the aftermath, which is practically guaranteed.

What If The Nukes Are Already In The Air?

If a North Korean missile makes it into the air, there are plans for that situation as well.

South Korea and Japan rely on tiered missile defense.

Stage two of South Korea’s three-stage defense system is the Korea Air and Missile Defense (KAMD) system, which is designed to intercept incoming missiles. The U.S. is bolstering South Korean defense through the deployment of a THAAD battery to South Korea, a process that began after North Korea fired four missiles into the Sea of Japan a few weeks ago.

THAAD’s Army Navy/Transportable Radar Surveillance (AN/TYP-2) X-band radar can be configured to one of two settings: forward-base mode and terminal mode. In the latter, the radar has a range of several hundred miles and can facilitate the elimination of missiles in the terminal phase of flight. In the former, the radar’s range is extended, making it possible for THAAD to target projectiles in the initial or launch phase.

To ease China’s concerns about the radar’s ability to peer into its territory, the U.S. has agreed to configure THAAD in terminal mode. China continues to express opposition to the deployment.

THAAD is an important step for South Korean missile defense.

“THAAD is better than anything South Korea has or will have for decades,” Bruce Klingner, who specializes in Korean and Japanese affairs as the senior research fellow for Northeast Asia at the Heritage Foundation, told TheDCNF, “It is imperative that we deploy it to augment the defense of Korea and the U.S. forces deployed there.”

There are also a number of Aegis destroyers operating in the waters off of South Korea. The U.S. has several in the region; Japan has six, and South Korea has three. The Aegis ballistic missile system can track multiple missiles simultaneously and intercept enemy projectiles as needed.

There are certain gaps in South Korea’s defense though. For starters, South Korea’s KAMD is not incorporated into the broader allied defense system, thus weakening its overall effectiveness. Also, the South is particularly vulnerable to submarine-launched ballistic missiles, which the North successfully tested last year.

Japan is much more “forward leaning” in its defense, Klingner notes. Japan has Patriot Advanced Capability (PAC)-2 and 3 systems, Aegis destroyers and SM-3 interceptors, and Japan is considering deploying THAAD and Aegis Ashore units on Japanese soil to boost national defense.

The U.S. has ground-based midcourse defense systems in Fort Greely, Alaska and Vandenberg Air Force Base, California.

Anti-missile systems have their limitations though.

Klingner remarked that “certainly, there is that possibility” that a nuclear-armed ballistic missile could slip through allied defenses, especially given that most regional missile defense systems have never been tested in actual battle conditions.

“Missile defenses help reduce the threat, but they can’t eliminate it,” Jeffrey Lewis, the director of the East Asia Nonproliferation Program in the James Martin Center for Nonproliferation Studies at the Middlebury Institute of International Studies at Monterey, commented.

In the simplest of terms, missile defense involves hitting a bullet with another bullet, which is no easy task.

“Missile defense systems will never provide 100 percent effectiveness … The addition of THAAD does not guarantee the protection of Seoul, but it does add another piece to the constantly changing puzzle of defense,” Rodger Baker, Vice President of Strategic Analysis at Stratfor, a geopolitical intelligence platform, told TheDCNF.

North Korea is rapidly developing the capabilities necessary to skirt allied ballistic missile defense systems.

“North Korea can probably build missiles (especially ER Scuds) faster and more cheaply than we can build and deploy defenses,” Lewis noted. In recent weapons tests and military drills, North Korea has practiced firing off multiple missiles in rapid succession or simultaneously to overwhelm enemy missile defense systems.

“This is a tactic called ‘salvo fire,’ which is designed to place greater stress on all types of ballistic missile defenses. I don’t know how many simultaneous attacks it would take to ‘saturate’ the battle-management systems in use today by the U.S., South Korean, or Japanese militaries, but the North Koreans seem determined to refine their salvo capabilities,” Joshua Pollack, editor of The Nonproliferation Review and senior research associate in the James Martin Center for Nonproliferation Studies at the Middlebury Institute of International Studies at Monterey, told TheDCNF. “Even if it didn’t succeed in saturating the defenses, it would at least more rapidly deplete the defense, which has a limited number of shots.”

“Enough simultaneous launches could overwhelm the THAAD system and increase the risk of a nuclear-armed ballistic missile reaching its target in South Korea,” Kelsey Davenport, director of Nonproliferation Policy at the Arms Control Institute, told TheDCNF after North Korea launched three missiles at the same time last September.

The simultaneous launch of multiple missiles is “basic missile defense countermeasure,” Lewis told CNN. “One THAAD battery is not enough. We need at least two, if not many more,” he told TheDCNF.

“The good news is that if defenses hold up against the first salvo, it’s much easier to locate mobile missiles after they fire than before,” Pollack explained, adding, “Ballistic missiles are very hot and bright upon launch, so the point of origin can be detected by satellites very rapidly. Perhaps the empty North Korean missile launch vehicles could be hunted down before they have the chance to reload,” but there is no guarantee.

What Would Be The Post-Launch Reaction?

Many people assume that in the event that North Korea carried out a nuclear strike, successful or not, the U.S. would use nuclear weapons to turn the North into a crater.

If they use a nuclear weapon, do we want to pave Pyongyang and kill a million citizens? If the intent is to take out the leadership and that can be done with precision guided munitions, is it in global interests to use nuclear weapons? The answer is unclear.

“U.S. nuclear strategy is evolving away from an automatic ‘they use nukes, we use nukes, we take out every city they have’ response,” Klingner told TheDCNF, adding that if North Korea launches a nuclear strike, “it may not be an automatic nuclear response if we can accomplish our objectives through other means.”

The decision to use nuclear weapons to retaliate against North Korea would be a political decision, one likely based on the resulting public outcry, as well as the target and whether the attack was successful or not.

“The United States maintains and updates numerous scenarios for potential military contingencies, and ones regarding North Korea are frequently reviewed,” Baker told TheDCNF, “A limited North Korean action may initially engender a large U.S. military buildup and emergency action in the United Nations, but full military intervention would not likely be far behind.”

Once war breaks out, the situation quickly becomes much more complicated. The U.S. and its allies have the advantage, but any war on the peninsula would almost certainly be a high-casualty conflict.

While South Korea and Japan have their own armed forces, they would still be largely reliant on the U.S. for defense in the event of a serious crisis. South Korea does, however, have an independent strategy known as the Korea Massive Punishment and Retaliation (KMPR) plan, the third phase of the country’s three-stage defense.

The KMPR plan involves using special forces to cripple North Korean assets and eliminate the leadership. The South would also mobilize its missile and artillery forces.

South Korea’s KMPR plan focuses on the complete annihilation of certain essential pockets of Pyongyang.

“The North’s capital city will be reduced to ashes and removed from the map,” an unnamed defense official revealed to The Korea Times, “Every Pyongyang district, particularly where the North Korean leadership is possibly hidden, will be completely destroyed by ballistic missiles and high-explosive shells.”

Japan is considering developing defensive, counter-attack capabilities, but those discussions are still in the early phases.

Relying on conventional weapons alone, North Korea is unlikely to survive a protracted military conflict, but this is where multiple weapons of mass destruction come into play.

“North Korea could potentially cause massive damage to Seoul and its surrounding areas” in a conflict, Dr. Bruce Bennett, a senior defense researcher at the RAND Corporation, previously told TheDCNF. “If North Korea restrains itself and only employs conventional weapons in an assault on South Korea, it is unlikely to overwhelm South Korea’s defenses. But if it uses weapons of mass destruction and other asymmetric approaches, the North may be able to overcome South Korean defenses — there are always large uncertainties in any war.”

“I’m confident of the outcome of that war, which would be the defeat of North Korea,” former Secretary of Defense Ash Carter told ABC reporters, “I need to caution you … This is a war that would have an intensity of violence associated with it that we haven’t seen since the last Korean War. Seoul is right there on the borders of the DMZ, so even though the outcome is certain, it is a very destructive war.”

Who Would North Korea Bomb?

The North regularly threatens nuclear war against the U.S., which is perceived in Pyongyang as the greatest threat to the country’s long-term survival. It is unlikely, however, that North Korea has developed the long-range missile technology required to strike the continental U.S.

Still, the North is working tirelessly to develop a reliable, nuclear-armed intercontinental ballistic missile and may be there in a matter of years.

“There is a real possibility that North Korea will be able to hit the U.S. with a nuclear-armed missile by the end of the first Trump term,” K.T. McFarland, the deputy White House national security adviser, previously remarked.

“We don’t know where they are on the path, but we know what path they are on,” Klingner told TheDCNF.

North Korea has launched satellites using Taepodong-style rockets, which could potentially serve as the technological foundation for an ICBM. The country has developed improved rocket engines that are better than most experts previously suspected. Also, the North appears to be working on two road-mobile ICBMs, the KN-08 and KN-14.

But, while the North has made clear progress, they have not yet demonstrated re-entry vehicle capability, and they are still developing a suitable nuclear warhead.

Were North Korea to launch a nuclear-armed missile at a foreign enemy, the two countries most likely to find themselves in the cross hairs are South Korea and Japan, collectively home to roughly 180 million people and around 75,000 U.S. troops. In the event that North Korea decided to fire on either of these two countries, a decision which the North would not take lightly, the Korean People’s Army could strike military bases and strategic assets, densely-populated civilian targets, or both.

Particularly disconcerting is that “the North Koreans say both,” Lewis explained to TheDCNF. “They hope the shock will cause us to recoil, and if it does not, they hope the damage slows us down.”

Several years ago, Pyongyang vowed that Tokyo would be “consumed in nuclear flames,” and early last year, the North threatened to turn Seoul into a “sea of flames.” Such threats are extremely common.

At the same time, North Korea has threatened, and even trained, to strike strategic assets, major ports, and critical military bases.

Days after the U.S. and South Korea announced plans to deploy a Terminal High Altitude Area Defense (THAAD) missile shield on South Korean soil, the North said it would turn Seongju, the deployment site, into a “sea of fire and a pile of ashes.”

When U.S. troops conduct joint military drills with allies for a possible conflict on the Korean peninsula, North Korea often drills as well, typically for a conventional or nuclear strike on allied troops, weapons, and defense systems.

During last year’s Foal Eagle drills, annual joint military exercises between the U.S. and South Korea for a contingency on the peninsula, North Korea launched two short-range missiles into waters off its east coast. “If we push the buttons to annihilate the enemies even right now, all bases of provocations will be reduced to seas in flames and ashes,” the North’s state-run Korean Central News Agency reported at the time. Images of the maps from the launch and open source analysis indicate that the Korean People’s Army was rehearsing an attack on the port of Busan, where the USS Ohio, a nuclear-powered submarine, had just arrived for a port call.

North Korea fired four extended-range scuds into the Sea of Japan during this year’s drills. KCNA reported that the artillerymen of the KPA were “tasked to strike the bases of the U.S. imperialist aggressor forces in Japan.”

Open-source analysis of the maps shown in the North Korean propaganda videos following the launch suggested that North Korea was simulating a nuclear attack on U.S. Marine Corps Air Station Iwakuni in Japan, where the only forward-deployed squadron of Marine Corps F-35s is stationed.

“The U.S. and South Korea are practicing invading North Korea. North Korea is practicing nuking those forces,” Lewis previously told TheDCNF, noting a distinct change in North Korean missile launches.

Weapons reliability, as well as possible reunification goals, could impact North Korea’s choice of target.

“North Korean missiles, while improved, are still not all that accurate. Thus, while Pyongyang may prefer to target U.S. military facilities in Japan with its limited nuclear arsenal, it may also choose to fire some missiles toward large population centers in an attempt to rapidly shift the political cost of conflict,” Baker told TheDCNF. “Pyongyang is less likely to use its nuclear arsenal in strikes on South Korea, but may use chemical weapons to disrupt and slow any U.S. advance,” he further commented.

Why Would North Korea Launch A Nuclear Missile?

[dcquiz]N orth Korea believes that nuclear bombs are the only things that can guarantee the country’s survival.

North Korea asserts that it fears nothing and will obliterate the U.S. and its allies with its “treasured nuclear sword,” yet the reality is that Pyongyang is deeply concerned that it may one day cease to exist, that it will be destroyed by the U.S. and its strategic partners. As its future is perpetually uncertain, the North believes that the only viable long-term security option is the development of nuclear weaponry.

Kim Jong-un’s fears are major factors in whether or not North Korea decides to launch a nuclear strike against another country. “I think that Kim Jong-un will press the button if his rule and his dynasty are threatened,” Thae Yong-ho, a former North Korean official who defected last year, explained. “He may do anything.”

“Putting this in a North Korean perspective, they see themselves as facing the world’s largest single military and nuclear power in a potential conflict. The pursuit of nuclear weapons, then, is intended as a deterrent, to counter their weaker military position,” Baker explained.

North Korea’s primary aspiration is “to stop a buildup of U.S. forces around them and protect North Korea from the fate of Iraq,” Pollack told TheDCNF. The aim is primarily nuclear deterrence.

Were North Korea to use a nuclear weapon, it would most likely be in the event of a conflict, if a conflict appeared imminent, or if some external factor posed an immediate threat to the country’s survival. How each side perceives these conditions varies, making it difficult to determine which actions might push the Pyongyang over the edge.

“It is not clear, for example, if they consider a limited strike against their nuclear or missile facilities as an imminent threat, or if they would initially respond with conventional systems,” Baker explained, “Though given the military disparity, even a limited strike could be seen as the beginning of a more concerned military effort, leaving the North needing to use its WMDs quickly or risk having its capability knocked out.”

Despite North Korean threats, the probability that North Korea would choose to launch a nuclear strike is relatively low, but at the end of the day, Kim Jong-un, while not irrational or crazy as some suspect, is very much a two-dimensional thinker who might decide to do the unthinkable if push came to shove.

The North Korean nuclear threat is one that has puzzled world leaders for decades, and the North’s arsenal of ballistic missiles and nuclear weaponry is growing with each passing day. “There are, at the moment, no constraints that would prevent North Korea from expanding its arsenal,” Lewis explained, “We might not like the North Koreans, but they’ve pretty much found a way to make sure we have to deal with them.”

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