The purpose of this paper is to look at USN's efforts to rebuild its combat power in the face of a reemergence of great powers competition, and to propose some recommendations for the ROKN. In addition to the plan to augment its fleet towards a 355-ships capacity, the USN is pursuing to improve exponentially combat lethality(quality) of its existing fleet by means of innovative science and technology. In other words, the USN is putting its utmost efforts to improve readiness of current forces, to modernize maintenance facilities such as naval shipyards, and simultaneously to invest in innovative weapons system R&D for the future. After all, the USN seems to pursue innovations in advanced military Science & Technology as the best way to ensure continued supremacy in the coming strategic competition between great powers. However, it is to be seen whether the USN can smoothly continue these efforts to rebuild combat strength vis-a-vis its new competition peers, namely China and Russian navy, due to the stringent fiscal constraints, originating, among others, from the 2011 Budget Control Act effective yet. Then, it seems to be China's unilateral and assertive behaviors to expand its maritime jurisdiction in the South China Sea that drives the USN's rebuild-up efforts of the future. Now, some changes began to be perceived in the basic framework of the hitherto regional maritime security, in the name of declining sea control of the USN as well as withering maritime order based on international law and norms. However, the ROK-US alliance system is the most excellent security mechanism upon which the ROK, as a trading power, depends for its survival and prosperity. In addition, as denuclearization of North Korea seems to take significant time and efforts to accomplish in the years to come, nuclear umbrella and extended deterrence by the US is still noting but indispensible for the security of the ROK. In this connection, the naval cooperation between ROKN and USN should be seen and strengthened as the most important deterrents to North Korean nuclear and missile threats, as well as to potential maritime provocation by neighboring countries. Based on these observations, this paper argues that the ROK Navy should try to expand its own deterrent capability by pursuing selective technological innovation in order to prevent this country's destiny from being dictated by other powers. In doing so, however, it may be too risky for the ROK to pursue the emerging, disruptive innovative technologies such as rail gun, hypersonic weapon... etc., due to enormous budget, time, and very thin chance of success. This paper recommends, therefore, to carefully select and extensively invest on the most cost-effective technological innovations, suitable in the operational environments of the ROK. In particular, this paper stresses the following six areas as most potential naval innovations for the ROK Navy: long range precision strike; air and missile defense at sea; ASW with various unmanned maritime system (UMS) such as USV, UUV based on advanced hydraulic acoustic sensor (Sonar) technology; network; digitalization for the use of AI and big data; and nuclear-powered attack submarines as a strategic deterrent.

The U.S. has recently developed Free and Open Indo-Pacific strategy and Distributed Lethality strategy based on a common perception that they are responding to China's threats. In the future, it is anticipated the following. Strengthen cooperation of the U.S.-India-Vietnam navy, Maximizing the combined combat power between the U.S. and regional navies, Improving its ability to restore damage control, Economic cooperation between the Pacific and Indian countries. The meanings given to the Korean navy are as follows. First, South Korea should pursue cooperation with the Indian Navy, which will grow into a regional balance on China's growth. The growth of the Indian navy is expected to increase cooperation with other Pacific countries. The government should seek ways to promote cooperation with india navy in various fields. Secondly, it is a joint drill between the U.S. Navy and the Korean Navy. Recently, the Korea-U.S. joint drill has not been conducted and many changes are expected to be made regarding the implementation of the joint drill in the future. Therefore, it is necessary to respond to possible changes in the naval relationship between Korea navy and the U.S. navy Also, due to distributed lethality strategy, preparations for operations and training with U.S.navy will be necessary. Lastly, it should contribute to cooperation among regional countries in preparation for maritime territorial disputes. The growth of the Chinese navy and the territorial disputes in the East and South China sea has raised the possibility of accidental military clashes at sea. Therefore, the government should make efforts to create multilateral security cooperation systems that can continue to promote the prevention of armed conflict.

The core of the current constitutional amendment pursued by the Abe administration depends on the status of the Japanese Self-Defense Forces, which include the right to engage in war, in the legal and regular military positions. This is an important turning point for the Abe administration, which aims to become a normal country for Japan, and it is a series of steps that followed in the revision of the U.S. and Japan guidelines in 2015 and the overhaul of the security law in 2016. In this paper, we propose building "A navy Attractive to Alliances" as a way to secure Korea's maritime security under the current security environment. The term "attraction" refers to the alliance "first priority" especially in the United States. The way to do this is to transform the paradigm of the ROK-U.S. alliance into a naval hub in the vast seas, which will allow us to strengthen our national defense and even deter threats from neighboring countries. To this end, our navy needs to have a more active approach to U.S. East Asian strategy. If we can convince the United States to be a nation that contributes more to its East Asian strategy, it will only lead to a strengthening of the status of its alliance and expansion of its unilateral support and military capability against Japan, thus minimizing Japan's influence.

2015년 미 해군에서 발간한 미 수상함대전략(Surface Force Strategy)에 따르면, 미 해군은 반접근-지역거부(Anti-Acess and Anti-Denial, A2/AD) 전략에 대한 대응책으로 '분산된 치명성(Distributed Lethality, DL)'이라는 신 작전개념을 개발 중에 있다. 이 개념은 각 유닛(unit)의 공격력(offensive power)을 향상시키고 지리적으로 분산 시킴으로써(geographical dispersion) 생존성을 향상시키는데 목적을 두고 있다. 하지만 동맹국(한국/일본 등)이 '분산된 치명성(DL)' 개념에 기여할 수 있는 영역이 다양함에도 불구하고, 지금까지 미 해군 내에서는 동맹국과 어떻게 공조해야 할 것인가에 대한 논의가 부족한 것이 사실이다. 따라서, 미 해군은 향후 '분산된 치명성(DL)' 이라는 작전개념에 동맹국이 줄 수 있는 이점을 추가적으로 적용하는 '동맹국을 활용한 분산된 치명성(Distributed Lethality with Allies, DL+A)' 개념을 발전시켜야 할 것이다. '동맹국을 활용한 분산된 치명성(DL+A)' 개념이란 동맹국이 가지고 있는 전력, 시설, 플랫폼 등 가용자산을 최대한 활용하여 기존의 '분산된 치명성(DL)' 개념을 강화시키는 신 작전개념이다. 미 해군은 본 논문에서 제시하는 신 작전개념(DL+A)을 적용함으로써 다양한 영역(정찰, 군수, 지리적 요충지, 플랫폼)에서 동맹국으로부터 지원을 받을 수 있을 것이다. 또한, 동맹국은 미 해군의 신 작전개념을 적용함으로써 A2/AD 전략에 대비한 안보능력을 향상시킬 수 있을 것이다.

As the South China Sea maritime dispute illustrates, when considering the place where maritime claims occur, states do not have many choices to respond to maritime claims in which disputed areas are located far away from the land and are surrounded by the sea. As Mearsheimer (2014) points out, the sea stops power projection. Therefore, in order to adopt coercive as well as peaceful settlement policies to deal with maritime claims, states need to overcome obstacles (the sea) to project power. It means that if states want to conduct a specific foreign policy action, such as negotiating maritime borderlines or arguing sovereignty on islands, they need a tool (naval power) to coerce or to persuade the opponent. However, there are lack of research that studies maritime claims from the perspective of naval power. This research project fills this gap based on naval power. How do relative levels of naval power and (dis) parities of naval power influence the occurrence of MIDs over maritime claims? Naval power is a constitutive element during maritime claims. If disputants over maritime claims have required naval power to project their capability, it means that they have the capability to apply various ways, such as aggressive options including MIDs, to accomplish their goals. So, I argue that when two claimants have enough naval power to project their capabilities, the likelihood of MIDs over maritime claims increases. Given that one or both states have a certain level of naval power, how does relative naval power between two claimants influence the management of maritime claims? Based on the power transition theory, I argue that when the disparities of relative naval power between claimants becomes distinctive, militarized conflicts surrounding maritime territory are less probable. Based on the ICOW project which codes maritime claims from 1900 to 2001, the empirical results of the Poisson models show if both claimants have projectable naval power, the occurrence of MIDs over maritime claims increases. In addition, the result shows that when disputants maintain similar relative naval powers, they are more likely to initiate MIDs over maritime claims. To put it differently, if naval capabilities' gap between two claimants becomes larger, the probability of the occurrence of MIDs decreases.

So far, the main threat to South Korea was North Korea. That is why South Korea established a strategy based on the threat of North Korea and most of the budget on defense was used to deter North Korea. Even though the neighboring countries(China, Japan, and Russia) are growing as a real threat with abilities and intentions based on their powerful naval forces, South Korea has not yet been able to establish a strategy that regards neighboring countries as a threat. But the decades-old structural mechanism of the Korean security environment is undergoing a radical change on April 27, 2018, through the South-North summit and the Panmunjom Declaration. Under the changing security environment, South Korea was placed in a complicated dilemma that had to deal with threats of two axes(China), three axes(China, Japan), and four axes(Japan, Russia). If the one axis threat(North Korea) is dominated by land threats, the second, third and fourth axis threats are threats from the sea. This paper analyzed the maritime strategy of Korea within the framework of maritime-geopolitics, in other words recognition and expansion of the sphere of maritime. I have designed that the maritime defense space that we can deny from threats is divided into three lines of defense: 1 line (radius 3,000km), 2 lines (2,000km), and 3 lines (1,000km). The three defense zones of the three lines were defined as an active defense(1 line), defensive offense(2 line), active offense(3 line). The three defense zones of the three lines were defined as the sphere of core maritime, As a power to deny the sphere of core maritime, it was analyzed as a maneuvering unit, a nuclear-powered submarine, the establishment of missile strategy, and the fortification of islands station. The marine strategy of South Korea with these concepts and means was defined as 'Offensive Maritime Denial Strategy'.

The purpose of this article is to examine the 'Discussion of maritime defense' which began to be discussed from the late Goryeo dynasty to the early Joseon dynasty and the process of establishing a maritime defense system. Also it can identify changes in the aspects of the naval ship operation and their strategic tactics during the reign of King Sejong. Japanese raiders began a full-scale invasion from 1350 at the late Goryeo Dynasty, So the government realized the need to raise the 'Sea power' and to organize the maritime defense system for defending enemy invasion. for example, the reinforcement of naval forces, construction of warships, develoment of weapon systems and so on. which have achieved remarkable growth while continuing, have also been used to carry out a three-time 'Conquest of Daemado' in 1389, 1396, 1419. Until then, however, it is difficult to interpret that the naval forces had a systematic and organizational combat operation system. According to fighting patterns on combat reports before the early days of King Sejong's reign, Our naval forces had no advantage over the Japanese raiders in terms of their capabilities and tactics. Then, the period of King Sejong marked a watershed in maritime defense history. Based on accumulated experience of naval battles and force Projections, The paradigm shift of the naval strategic tactics for maritime defense has occurred. First, the capability of the naval vessels has improved. for example, ship speed, durability, and weather resistance. Through these efforts, navy forces were able to pursue and attack, destroy enemy's ships by taking advantage of the 'Ship speed superiority'. This has led to tactical shifts from defensive to offensive. Second, purpose to support offensive tactics, the government put a strategic plan into practice that is the forward depolyment of naval bases from the inland to the coast, considering the 'sea environment' and 'threat'. By doing so, Joseon dynasty was able to secure 'the command of the sea'. This may be a little different from the perception of the so-called 'peace period' that King Sejong's era. We need to remember that Joseon dynasty was working hard for its defense. When studying history of maritime defense, these strategic and tactical elements must be fully considered. Only then we can have a coherent understanding of the many naval battles in the past, including the Imjin War(1592-1598).

The Russo-Japanese War(1904-1905) in the early 20th century greatly influenced the international politics in Northeast Asia and the destiny of both countries. There are many studies on the cause of the outbreak and its effect on the Korean peninsula. The victory and defeat of the battle of Tsushima also the subject of research by renowned scholars and navy officers. Many previous studies have analyzed the process of engagement. However, There was a lack of research that analyzed at the tactical level of naval commanders. Therefore, this study tries to review the battle of Tsushima in terms of tactical level, that is formation, maneuvering, damage control. Naval operations at sea with many variables are not always done as planned. The intuitive judgement and readiness have had a decisive impact on victory and defeat. The analysis of the naval warfare on the basis of formation, maneuvering, and damage control makes the cause of the win more clearly. The conclusion of the this study can be summarized in five ways. First, victory would be achieved through the suppression of the beginning. The destiny of the Tsushima battle was determined by an 1 hour after first firing. The Japanese fleet caught fire by paralyzing the command and control capabilities of the Russian fleet. Second, the Japanese fleet's power was superior to the Russian fleet. In general, Japan and Russia had similar powers, and Admiral Togo's "T crossing tactics" decisively contributed the victory. However, when compared to the weapon system level, formation and maneuvering, Japan was much more dominant. Third, people realized that one side to be annihilated in the battle between similar powers after the Tsushima battle. The common perception before the Battle of Tsushima was that the battle ship would not sunken, and that the result of wiping out was difficult. However, there is s time for one sided victory and defeat depending on the early suppression nad the destruction of the command and control ability. Fourth, it is the importance of damage control ability. The main cause of the Russian fleet's loss of command and control ability was thick smoke from fire, and maneuverability was greatly deteriorated due to coal overload. In this way, importance is still valid after more than 100 tears. Fifth, the area of uncertainty. In the navy battles, one or two shots of clear firing in the beginning and small misconception and minor mistakes decide win or loss. Ultimately, this area of fortune can be linked to mindset of the commander. I hope this research will be help to naval researchers and naval commanders at the sea.

Why did Kim Jong Un turn his foreign policy upside down in a sudden? US naval blockade became one of candidates for the reason since it had been threatened by Trump administration for the first time in December 2017. Has the blockades worked well like that in the international politic history? This paper reveals the effectiveness of naval blockade on sanctioning in the peacetime. This research analyzes three hypothetical arguments about the naval blockade based on the result of empirical tests with TIES Dataset. First, sanctions by blockading are more effective in gaining political benefits than the other economic sanctions. It was ranked the 4th effective way of sanction out of 9. And 56.3% of pacific naval blockades without packaged economic sanctions were succeeded, whereas the possibility of success increase up to 61.2% when blockade has been imposed in accordance with the other type of economic sanctions. Second, blockades deter military collisions, even war. When it comes to military provocation issue, blockading sanctions gain political interest far more than the other type of economic sanctions. The possibility of the success reaches up to 74%. Also, there wasn't any historical cases of war incurred by blockading sanctions within 5 years after the blockade end. Third, policy makers just need 1.2 years on average to see the end of sanctions when they choose the naval blockade as the method of imposing sanction on the adversary. It is impressively short span of time in achieving political goal compared to the other types of sanctions which are need 9 years on average. North East Asia sea could be the next stage for a naval blockade sooner or later. Because China and Japan not only possess capabilities of blockade but also have will to impose blockades to the others if conditions are set. And even the North Korea with lots of submerging forces could be a blockading threat in the specific area. So, the Republic of Korea has to pay more attention and be prepared for naval blockading sanction.

This research aims to cast light upon security characteristics of the Peace Line, which have been underestimated. To understand maritime order and maritime security policy of the Republic of Korea between 1950 and 1970, it is necessary to analyze the Peace Line as line of defence and to investigate its character This research begins with analyzation of historical facts and investigation on security characteristics of the Peace Line. It goes further to examination of legal justification of the Peace Line, which was one of international legal issues of the period, principally regarding its security characteristics. As results of the study, it could be said that the security characteristics of the Peace Line was the line of defensive waters, which set its goal mainly to prevent infiltration of communist spies. The Peace Line had practical effect as it functioned as a base line of the ROK Navy to take anti-spy operation. At the early phase of the Korea-Japan Negotiation, the Korea delegation interpreted significance of the Peace Line passively. After abrogation of Clark Line, the delegation, however, became positive to maintain the Peace Line and its security characteristics. Security characteristics of the Peace Line was recognized again, as it became the base line of special maritime zone which was made in 1972. Through analysis on international law, it is concluded that the Peace Line was fair as a part of the right of self-defense against indirect aggression. North Korea attempted indirect aggression mainly from sea way, and these might undermine peace and cause urgent and unjust damage on the ROK. Thus the ROK's action of anti-spy operation through the Peace Line can be justifiable as considering the right of self-defence. Also the Peace Line accorded with principles of necessity, immediacy and proportionality. As it was argued on the above, the Peace Line as line of defence was one of the most significant factor in the ROK's maritime security history from the Hot war against communist forces to Cold war period after Korean War and must not be underestimated.

Adopted in Western Pacific Naval Symposium(WPNS) 2014, Code for Unplanned Encounters at Sea(CUES) has been the most valuable output of WPNS history. Written and suggested by Australian Navy in 1999, the goal of CUES is to decrease the possibility of the naval conflict by establishing the code among international navies in the Western Pacific region. Facing many oppositions and requirement of People's Liberation Army Navy(PLAN) in WPNS 2012 and 2013, but it finally adopted in WPNS 2014, with many changes in detailed provisions. From then, navies in the Western Pacific region have followed CUES to prevent maritime conflicts in the region, CUES, however, sometimes does not work correctly. Contents of CUES is the mixture of the parts of Multinational Maritime Tactical Signal and Maneuvering Book(MTP) and International Regulations for Preventing Collision at Sea 1972(CORLEGs). There are means of radio communications such as frequency and signals, instructions for maneuvering and so on. Thus, it is not a new document for the U.S. Navy and its allies, but it requires training to implicate at sea for navies other than U.S. allies, like PLAN. Lots of provisions in CUES were changed because of the opposition of PLAN, and CUES has many shortcomings and practical limitations. First, since CUES is non-legally binding, and there are no methods to force the naval assets on the sea to follow. Second, CUES is only applied to naval assets; naval ships - warships, naval auxiliaries, and submarines - and naval aircraft. Third, the geographical scope in CUES is not clear. Fourth, there is no provision for submerged submarines. Finally, CUES has no time-based framework or roadmap for training. In this regard, there would be six recommendations for improvement. First, CUES should be reviewed by WPNS or other international institutions, while keeping non-binding status so that WPNS could send signals to the navies which do not answer CUES on the sea. Second, the participation of Maritime Law Enforcements(MLEs) such as coast guard is inevitable. Third, navies would use full text of MTP rather than current CUES, which extracts some parts of MTP. Fourth, CUES needs provisions with respect to submerged submarines, which recognizes as offensive weapons themselves. Fifth, the geographic scope of CUES should be clear. Since there are some countries in which claim that a rock with a concrete structure is their territory, CUES should be applied on every sea including EEZ and territorial seas. Finally, the detailed training plan is required to implicate CUES at sea. Rim of the Pacific (RIMPAC) is a good exercise to train CUES, because almost all WPNS member countries except six countries are participating in RIMPAC. CUES is a meaningful document not only for navies but also for nation-states in the region. To prevent escalation of conflict in the region, potentially caused by an unplanned collision at sea, CUES should be applied more strictly. CUES will continue to be in subsequent WPNS and therefore continue to improve in the effectiveness as both an operational and diplomatic agreement.

Through this research, the current state of naval coordination and guidance of shipping is reviewed whereupon which a suggestion is made for a novel role which satisfies the needs of the people and the country asked of the Navy. Taking into consideration the dynamic security environment, the developing relationship between the two nations on the Korean peninsula, and the influence that the Republic of Korea has on maritime security, it is made more urgent that the Navy takes a proactive course of action in terms of naval coordination and guidance of shipping. The current form of Korean naval coordination and guidance of shipping is adapted from the logical and flexible concepts of NCAPS and NCAGS and is one of many tasks that the Republic of Korea Navy must perform. However, when the Republic of Korea Navy develops blue-water capabilities with the ambitions of protecting its people and their way of life, naval coordination and guidance of shipping could potentially become one of the primary functions of the Republic of Korea Navy that the it must champion. Already, there are indications that foreign navies are, through many developments and commitment towards naval coordination and guidance of shipping, protecting its people and states' interests wherever is necessary. In the case of Chile, its Navy has taken the helm of naval coordination and guidance of shipping and has integrated various maritime organizations including the coast guard and the National Customs Service for the sake of maintaining regional maritime security, showing immediate force if necessary. Presently, as the Republic of Korea Navy looks to be a global naval power, it is important that a reprioritization of the Navy's mission is undertaken, all the while sustaining military readiness posture on the Northern Limit Line. It cannot be any more emphasized how crucial thorough military readiness posture is as a natural stance against the enemy. That being said, contributing towards international maritime security is consistent with the nation's standing. It is a fact that maritime security has been conceptualized and developed merely as a study within the Ministry of Maritime Affairs and Fisheries, the Republic of Korea Navy, and other governmental organizations, forces, and academia. Naval cooperation and guidance of shipping suggested by this research as a practical operational field is a concrete solution to what once was an abstract concept. To stand firm on its status as a maritime nation, the Republic of Korea must establish a Maritime Security Organization within its Navy and develop the appropriate doctrines. Attaining experts, developing doctrines, and cultivating the capability to deploy maritime forces will allow for the Republic of Korea to execute a primary role in keeping international maritime security and naval coordination and guidance of shipping. To fully achieve its latent potential necessitates the Republic of Korea Navy to expedite the introduction of naval coordination and guidance of shipping concepts and to establish the appropriate doctrines, operation plans, and organizations.

The purpose of this study is to investigate the effects of the job stresses perceived by R.O.K. naval crews on turnover intentions and job satisfactions. Especially, this study aims to derive the policy implication for the trait characteristics by comparing the job attitude between the surface naval ship and submarine crew. For this purpose, we surveyed 1,000 naval crews. Then, multiple regression analysis was performed. Next, a T-test was conducted to test statistical significance of group differences. First, the job stresses perceived by naval crews were higher in the order of physical environments, overworks, compensation incompetence, lacks of autonomy, and conflicts with people. Second, the job stresses perceived by submarine crews were higher than that of surface naval ship crews. It was also proved statistically significant by the T-test. Third, the physical environments, lacks of autonomy, conflicts of relativity, and inadequate compensation stress have a positive statistically significant effect on turnover intentions of naval crews. Fourth, lacks of autonomy, conflicts of relativity, and inadequate compensation factors have a statistically significant negative effect on the job satisfactions of naval crews. Finally, multiple regression analysis was performed between the independent and dependent variables of the naval crews, and the policy implications were derived.