US Mini-nukes and an analysis of a second Korean war
The Long Range stand off (LRSO) nuclear cruise missile program has been funded since 2013 and has received about $500 million in funding. The program will eventually cost $15-30 billion.
There have been calls to cancel it. The LRSO would have a variable-yield weapon using a modified W80 warhead. The Air Force wishes to procure: 1,000-1,100 LRSO. That looks like a significant increase in the number of air-launched cruise missiles available for bomber missions.
The Department of Energy is producing a new variant of the B61 gravity bomb that will be highly accurate and have a variable yield of 0.3 to 50 kilotons.
The existing (but to be retired) ALCM is believed to have a selectable yield of 5 KTs or 150 KTs. The lower yield is presumably for the boosted primary alone, and the larger yield for the two-stage weapon. The life-extension program for the W80 warhead, which will be carried by the LRSO missile, is expected to provide closer to a "dial-a-yield" option that would allow a number of yield options.
The US can destroy North Korea's air defenses using conventional weapons in about a week just as the US destroyed Air Defenses of Iraq. The question of whether missiles have more stealth or whether there is selectable nuclear yield on 1000 or 2000 nuclear weapons in the US arsenal is not significant. This is because the US can wage more limited nuclear war with lower yield nuclear weapons already.
Despite the thousands of artillery pieces, only 700 heavier guns and rocket launchers, plus the newer 300-millimeter MRLs, have the range to strike Seoul. Seoul has extensive air raid shelters for civilians that will quickly reduce the exposed population density. The North will struggle to keep these heavy artillery units supplied with shells, particularly with its aging supply system. Finally, U.S. and ROK forces will quickly begin hunting down units participating in the bombardment, causing their numbers to drop almost immediately.
North Korea occasionally threatens to "turn Seoul into a Sea of Fire". The South Korean, U.S. and other international media often relay this statement, amplifying its effect. But can North Korea really do this? Does it matter if they can? The short answer is they can't; but they can kill many tens of thousands of people, start a larger war and cause a tremendous amount of damage before ultimately losing their regime.
If the North Korean Peoples Army (KPA) were to start a doctrinal, conventional artillery barrage focused on South Korean forces, we could expect to see around three thousand casualties in the first few minutes, but the casualty rate would quickly drop as the surprise wears off and counter-battery fires slow down the North Korean rates of fire. If the KPA were to engage Seoul in a primarily counter-value fashion by firing into Seoul instead of primarily aiming at military targets, there would likely be around thirty-thousand casualties in a short amount of time. Statistically speaking, almost eight-hundred of those casualties would be foreigners given Seoul's international demographic. Chinese make up almost seventy percent of foreigners in Seoul and its northern environs which means KPA might also kill six-hundred Chinese diplomats, multi-national corporation leaders, and ranking cadre children who are students in Seoul. Horrible, but nothing approaching "millions". Three primary factors and three secondary factors account for the huge discrepancy between rhetoric and reality:
Note : The Nautilus analysis seems to imply that a US-South Korea first strike would blunt the initial North Korea damage rate and could limit early deaths to 10000 to 15000. There would be no initial rate of 3000 deaths in the first few minutes and there would be some pre-warning on the South Korea side to get people to shelters.
However, the protracted artillery and tank battle would still kill 80,000 in the first week. Overall deaths would be in the 100,000-150,000 range.
Three Primary Factors
* Range - Only about 1/3 of Seoul is presently in range from artillery along a DMZ trace. The northern reaches of Seoul within artillery range have much lower population densities than Seoul proper;
* Numbers - Even though KPA has a tremendous number of artillery pieces, only a certain number are emplaced to range Seoul. KPA can't emplace every weapon near Seoul or the rest of North Korea's expansive border would be unguarded and even more vulnerable. Moreover, an artillery tube immediately reveals its location as soon as it fires. Therefore only about two-thirds of artillery will open fire at a time. The rest are trying to remain hidden;
* Protection - Artillery shelters for twenty million people exist in the greater Seoul metropolitan area. After the initial surprise has worn off, there simply won't be large numbers of exposed people. Even during the initial attack the vast majority of people will either be at work, at home, or in transit. Few people will be standing in the middle of an open field with no protection whatsoever available anywhere nearby.
Three Secondary Factors
* Dud rate - the only numbers available-to the DPRK as well as the rest of the world-indicate a dud rate of twenty-five percent. It's like immediately taking every fourth artillery tube away.
* Counter-battery fires - shortly after the KPA artillery begins firing, and the political decision has been made, South Korean artillery, Air Forces, and others will begin destroying artillery at a historical rate of 1% per hour. South Korea has had approximately 50 years to figure out where North Korean artillery tubes are emplaced using every sense available to man and machine.
* Logistics - in order to move south from the DMZ trace and place the rest of Seoul at risk, KPA must expose approximately 2,500 thin-skinned vehicles each day along three well-defined transportation corridors. Otherwise, KPA grinds to an almost immediate halt without a way to transport fuel, ammunition and spare parts needed to continue moving south. Alternatively, KPA can scavenge from ROK fuel stores and depots if they have not been previously destroyed.
