Sejong Policy Briefs

(brief 2022-07)The Threshold of Nuclear War seen through the Ukraine Crisis

Date 2022-04-22 View 1,152

 

The Threshold of Nuclear War seen through the Ukraine Crisis 

- the controversy over low-yield nuclear weapons and limited nuclear war

 

Kim Jungsup

(jungsupkim@sejong.org)
Vice President,
the Sejong Institute

Executive Summary


■ The threat of Russia's nuclear use and low-yield nuclear weapons
○ As Russia repeatedly threatened to use nuclear weapons during the war in Ukraine, there are growing concerns that the use of nuclear weapons, which had never been imagined, may have entered the realm of possibility.
○ The existence of low-yield nuclear weapons has a certain impact on the possibility of breaking the nuclear taboo that has been maintained for more than 70 years.
○ Unlike strategic nuclear weapons, low-yield nuclear weapons, which have little collateral damage such as mass destruction of civilians, are emerging as weapons that can be used in battlefield due to low thresholds for nuclear use, and contemporary competition among nuclear powers, including the U.S. and Russia, is also underway. 

■ Controversy over the threshold and method of nuclear war
○ Recently, interests in low-yield nuclear weapons have increased, but questions of nuclear deterrence, such as the role of nuclear weapons, the threshold of nuclear war, and the method of nuclear war are long-standing controversies dating back to the Cold War. 
○ Whether nuclear weapons should remain a means of deterrence or a war-fighting force that can be deployed to the battlefield is a key issue in the history of nuclear strategy. 
○ A camp that emphasizes the deterrent nature of nuclear weapons focuses on strategic capability based on retaliatory threats, while another camp that focuses on the nature of actual combat capabilities pays attention to carrying out nuclear warfare in case of a collapse of deterrence. 
○ It is clear that unlimited all-out nuclear war, which causes the destruction of mankind, is nonsense. If a nuclear war breaks out, there is a concept of a limited nuclear war that must be carried out in a controlled and restricted manner.
○ In other words, deliberate restrictions on the selection of war targets, targets, and weapons to be used should be imposed in order to minimize damage to the military and to end the nuclear war with acceptable conditions.
○ However, there are arguments and objections regarding the theory of limited nuclear war, whether nuclear war can be controlled or whether lowering the threshold of nuclear weapons will increase the possibility of nuclear war.

■ Implications on the Korean Peninsula
○ The nature of the nuclear confrontation on the Korean Peninsula is no longer limited to the balance of fear, and the need to pay attention to the possibility of tactical use of low-yield nuclear weapons is increasing.
○ It is interpreted that North Korea is expanding asymmetrically without excluding the use of tactical nuclear weapons in normal conflict situations, and the modernization of low-yield nuclear weapons by the U.S. has also the effect of diversifying its nuclear options as a deterrent.
○ It is hard to deny that South Korea and the U.S. should prepare for the nuclear war in case North Korea's nuclear deterrence fails.
○ However, there is a dilemma that if one is obsessed with the possibility of deterrence failure, maximizing the option of using nuclear weapons and concentrating escalation dominance, it will trigger an arms race and undermine the stability of the crisis.

○ Therefore, it is necessary to develop a balanced deterrence strategy to harmonize the two demands of deterrence of nuclear use and countermeasures in case of its failure.