The Mahan's seapower theory has been the basis of US Navy to date as it can enjoy the supremacy status in all of the seas of the world. His theory is very straightforward. A nation can be a great country in the world just through the use of maritime commerce that could be protected by a strong and powerful navy. Mahan's theory on seapower was substantiated in the Spanish-American War with respect to how important the naval power is. The best thing to make US a great nation was to make sure that flow of international trade is smooth, and the unhindered trade could be made possible only by the destruction of enemy's fleet that may obstruct the SLOCs. That's why Mahan insisted that a strong navy was needed and a decisive battle by the navy's fleet at sea should be encouraged as a way of ensuring the safety of the SLOCs. The newly-arrived Trump administration seems to be in line with the Mahan's theory seapower in its policy on naval forces structure. It is expected that US will continue to support the Pivot to Asia policy that has been adopted by the previous administration through an increase in its naval fleet forces. The number of US navy ships will be 355 in 2030, rendering it much more powerful navy than before. The catch phrase "3rd Fleet Forward" proposed by the president Trump indicates that two carrier strike groups will be present in the Asia Pacific region, being able to make the confrontation between US and China more tense than before. The presence of the US naval forces in the area may function as some sort of pressure against China that Trump insisted had been responsible for the closure of 60,000 factories and the loss of 3,000,000 jobs in the United States.

Neighboring powers in the Korean Peninsula have started to develop and operate aircraft carriers or equivalent forces to cope with rising North Korean nuclear and missile threats and also to show its national might. For example, the United States has added a aircraft carrier from the 3rd fleet to western pacific theater of operation, while Peoples Republic of China is undergoing operational test of Liaoning as well as preparing for christening of its 2nd aircraft carrier. Japan is flexing its muscle as well by deploying Izumo capable of operating F-35B to Southeast Asia to participate in multilateral exercises starting this year. It is a high time to know more about aircraft carriers or similar types in terms of maritime strategy and history. The U.S. has had by far the vast amount of experiences in utilizing aircraft carrier that it would be beneficial for us to examine U.S. perspectives and its application in the Korean Peninsula. It will provide us with insights to understand and predict what it would be like in times of crisis in the Korean Peninsula in the perspective of aircraft carrier's involvement. This paper intends to show some aspects of future conflicts in the Korean Peninsula and how the ROK Navy can best be ready for such situation. For research purpose, U.S. maritime strategy has been developed in stages ; establishment phase, WWI phase, WWII phase, Cold war phase, post Cold war phase. Each phase includes such factors as threats, strategic concept, applications, and ways to improve maritime strategy. Finally, the role of aircraft carrier based on past history as well as future conflict shines the importance to have power projection capabilities for the ROK Navy. The intrinsic nature of the navy in the world is to project power ashore just as history proved it.

After finishing Cold War, the U.S. Navy's ability to Sea control has been gradually eroded last 15-20 years. The global security environment demands that the surface Navy rededicate itself to sea control, as a new group of potential adversaries is working to deny U.S. navy command of the sea. China has been increasing their sea denial capability, such as extended anti-surface cruise missile and anti-surface ballistic missile. To cope with this situation, the U.S. Naval Surface Forces Command has announced Surface Forces Strategy: Return to Sea Control. It is a new operating and organizing concept for the U.S. surface fleet called 'distributed lethality'. Under distributed lethality, offensive weapons such as new ASCMs are to be distributed more widely across all types of Navy surface ships, and new operational concept for Navy surface fleet's capability for attacking enemy ships and make it less possible for an enemy to cripple the U.S. fleet by concentrating its attack on a few very high-value Navy surface ships. By increasing the lethality of the surface ships and distributing them across wide areas, the Navy forces potential adversaries to not only consider the threat from our carrier-based aircraft and submarines, but they now consider the threat form all of those surface ships. This idea of using the distributed lethality template to generate surface action groups and adaptive force package and to start thinking about to increase the lethal efficacy of these ships. The U.S. Navy believes distributed lethality increases the Navy's sea control capability and expands U.S. conventional deterrence. Funding new weapons and renovated operating concept to field a more lethal and distributed force will enable us to establish sea control, even in contested area. The U.S. Navy's Surface Forces Strategy provides some useful implications for The ROK Navy. First the ROK Navy need to reconsider sea control mission. securing sea control and exploiting sea control are in a close connection. However, recently the ROK Navy only focuses on exploiting sea control, for instance land attack mission. the ROK Navy is required to reinvigorate sea control mission, such as anti-surface warfare and anti-air warfare. Second, the ROK Navy must seek the way to improve its warfighting capability. It can be achieved by developing high-edge weapons and designing renewed operating concept and embraced new weapon's extended capabilities.

The purpose of this article is to explore recent developments in piracy attacks at the global level. This article provides an overview of global trend of recent piracy attacks and presents global counter-piracy efforts at the international and governmental as well as industry level. The issue of piracy has been a grave concern of the globe, becoming the biggest threat to the safety and security navigation and seaborne trade. Overall, piracy attacks in recent years have greatly diminished owing to multi-faceted counter-piracy efforts. However, Southeast Asia and West Africa have reemerged as an hotspot of piracy. A worrisome trend in these regions is that many of piracy attacks are committed by militant groups for financing their activities. As a result, the level of violence and the sophistication of attacks have escalated. The problem of contemporary piracy is beyond a particular region or coastal state, but a common concern of the international community. In order to address the global piracy problem, international cooperation should be further strengthened at the global level as well as the regional level. As a way of counter-piracy measures in Southeast Asian waters, the creation of a joint regional coast guard to patrol the highly piracy concentration areas needs to be considered.

This paper aims to analyze hegemonic competition and the role of naval power. To this end the paper is composed of four chapters titled introduction, the role of naval power in the hegemonic competition, the role of naval power in the East Asia, and the lessons and implications for the Korean Peninsula. Since the modern era, the hegemonic competition in the East Asian region has been the intrusion and struggle process between the world system and the East Asian regional system, and the ocean between these two systems has become the goal and means of supremacy(hegemony). Currently, the hegemonic competition between the US and China consists of systemic competition at the global level and marine competition at the regional level. When South Korea is forced to make strategic choices in the course of the US-China hegemonic competition, naval power will be the first factor to be considered. The ROK is asymmetrically maintaining a deep dependency relationship with the United States in terms of security and China in relation to the economy. And while the ROK's national economic power is acquired from the ocean, the ROK's military power is imbalanced because it is centered on the ground forces. These international relations and asymmetric-unbalanced resources distribution will not be able to effectively cope with the hegemonic competition between the US and China in the future, and will limit Korea's strategic choice. Since naval power and forces are the prerequisites for the hegemonic competition or the maintenance of supremacy we must construct balanced naval forces(naval power) that are not subordinate to the ground forces at the national strategic level for the future of the country.

On 15 December 2015, China seized an underwater drone belonging to the U.S. in the South China Sea. The underwater drone was then about to be retrieved by the Bowditch, a U.S. naval ship.Although China returned the underwater drone to the U.S. on 20 December 2016, the incident resulted in the considerable controversy involving the use of underwater drones. The reason for this is that the seizure of the underwater drone happened in the exclusive economic zone (hereafter referred to as "EEZ") of the Philippines. Part XIII of the United Nations Convention on the Law of the Sea (hereafter referred to as "UNCLOS") governs the matters of marine scientific research (hereafter referred to as "MSR"). If a State intends to use an underwater drone in the EEZ of another coastal State for the purpose of MSR, the former has to obtain the consent of the latter in accordance with relevant provisions included in Part XIII of the UNCLOS. However, it is not obvious whether the consent of a coastal State should be required to launch an underwater drone in the EEZ of the State for the purpose of hydrographic surveying or military surveying. Maritime powers such as the U.S. regard hydrographic surveying or military surveying as part of "other internationally lawful uses of the sea related to these freedoms, such as those associated with the operation of ships, aircraft and submarine cables and pipelines" found in Article 58(1) of the UNCLOS, or part of the freedom of the high seas. This interpretation is not incompatible with the implications that the UNCLOS has. Nevertheless, Korea cannot accept this kind of interpretation that is supported by maritime powers. The freedom of hydrographic surveying or military surveying could imply that the EEZ of Korea would be full of underwater drones launched by China, Japan or even Russia. Hence, Korea should claim that the data collected for the purpose of MSR cannot be distinguished from that collected for the purpose of hydrographic surveying or military surveying. This means that hydrographic surveying or military surveying without the consent of a coastal State in the EEZ of the State should not be permitted.

Human history shows diverse strategies for survival and prosperity. This study introduces the concept of the expansion of wealth as a key to explain choice and behavior of political entities. American scholar, -Bruce Bueno de Mesquita-, offers theoretical grounds for this concept in that the cores of selectorate theory is settled. The political entity consists of two groups, -the winning coalition that has power to replace leader and non-winning coalition that has not. Leaders implement policies serving for the welfare of winning coalition in return for their loyalty. Both internal problems caused by demographic changes and external ones of climate changes, epidemic disease, or invasion compel leader and winning coalition to adopt policies of expansion that they believe may lead to the acquisition of wealth needed to counter those problems. The process starts by occupying one spot where other entities reside and then connecting it to its own. The line between spots functions as a foothold to form a new line to other spots. By repeating this process, a space is created in which new laws and orders are instated. In the early stage of expansion, war is hardly avoidable. Once finished successfully, the political circumstance tilts to encourage economic activities in order to generate national revenues to strengthen political power of winning coalition. However, as scale of economic activities grows, so does political power of civic classes in production and trade. To gain financial support required to run the political entity, delegation of power or bestowing autonomy to non-winning coalition is inevitable. Thus, expansion is not the ultimate solution, only to prolong the political survival if succeed. Maritime power came to attractive option when overland expansion had become obstructed. It offered much greater advantages in terms of political risks and financial burdens in exploring new regions of precious commodities than overland expansion. Each political entity around world have been, for the first time in human history, connected by maritime means since 15th century. It is worthy of noting that land conditions propelled people out to sea. Political and economic situations created opportunities to exploit geographical position in pursuit of wealth. In the 21st century, we witness the operation of international winning coalition that presides over the rules of expansion. Competing for market is synonymous to the expansion in this era, the cause and aim of it has not been changed though. Energy and dollars are key factors of expansion since the end of the 2nd world war. No matter what the forms and conditions change, naval power is still the most relevant means for expansion as it retains unique characters of maneuver, flexibility, continuity, display and projection of power. The strategy for using naval power should be in line with two different approaches for expansion: Approaches to the international winning coalition by making contribution to world order, and approaches to the non-international winning coalition by enhancing military diplomatic activities. The former will serve our share of winning coalition while the latter will open chances to acquire further prosperity.

The balance of power in conventional forces between the two Koreas works in favor of the South Korea in the Korea peninsula. But, the balancing mechanism between the two Koreas in asymmetric forces like nuclear and missile forces works absolutely in favor of the North Korea. That's why it should be timely for the ROK military to review existing strategy and revise a new counter strategy against the threat posed by the North Korea's nuclear and missile forces. The ROK military is now developing 4D, KAMD, KILL Chain strategies as means to cope with the North Korea's nuclear and missile threats. Considering efforts and resources invested now, the strategies are expected to be in place in next five or more years. However, approaches to those strategies seem to be rather fragmentary and conceptual than comprehensive and pragmatic. The types of strategies against the North Korea's military threats need to be a deterrence in peace time and a fighting and winning in war time in the Korean theater. But, the most important element in the deterrence strategy is the credibility. This study concludes with an new strategic concept titled "ADAD(Assured Defense, Assured Destruction)" as an alternative to existing strategies to deal with the North Korea's nuclear and missile threats.

The purpose of this paper is to open a debate about what kind of deterrent strategy the ROK military should pursue in the era of NK's weapons of mass destruction and missile threats. I argue that the ROK military needs a comprehensive deterrent strategy that reflects the international security situations and trends and that builds on clear understanding of the basic concepts and how deterrence operates. The paper starts with surveying the basic knowledge of deterrence from the perspectives of both theory and practice. Then, it provides explanations on why deterrence against NK can be particularly difficult given the security environment in and around the Korean peninsula. For example, South Korea and North Korea hardly share 'common knowledge' that serves as a basic element for the operation of deterrence. Deterrence against North Korea involves complex situations in that both deterrence and compellence strategies may be relevant particularly to North Korea's WMD and missile threats. It also involves both immediate and general deterrence. Based on the discussion, I suggest several ideas that may serve as guidelines for establishing a deterrent strategy against NK. First, our threats for deterrence should be the ones that can be realized, particularly in terms of the international norms. In other words, they must be considered appropriate among other nations in the international community. Second, there should be separate plans for the different kinds of threats: one is conventional, local provocations and the other is WMD/missile related provocations. Third, we should pursue much closer cooperative relations with the U.S. military to enhance the effectiveness of immediate deterrence in the Korean peninsula. Fourth, the ROK military should aim to accomplish 'smart deterrence' maximizing the benefits of technological superiority. Fifth, the ROK military readiness and structure should be able to deny emerging North Korean military threats such as the submarine-launched ballistic missiles and intercontinental ballistic missiles. Lastly, in executing threats, we should consider that the current action influences credibility and reputation of the ROK, which in turn affect the decisions for future provocations. North Korea's WMD/missile threats may soon become critical strategic-level threats to South Korea. In retrospect, the first debate on building a missile defense system in South Korea dates back to the 1980s. Mostly the debate has centered on whether or not South Korea's system should be integrated into the U.S. missile defense system. In the meantime, North Korea has become a small nuclear power that can threaten the United States with the ballistic missiles capability. If North Korea completes the SLBM program and loads the missiles on a submarine with improved underwater operation capability, then, South Korea may have to face the reality of power politics demonstrated by Thucydides through the Athenians: "The strong do what they have the power to do, the weak accept what they have to accept."

Nuclear power is a way of attaining an enormous amount of energy with relatively small amount of resources and after it has been introduced to the submarine since 1954, there are approximately 150 of nuclear powered submarine currently on a mission around the world. This is due to the maneuverability, mountability and covertness of nuclear submarines. However, there are other tasks, not only the high level of nuclear technology that are needed to be dealt with in order to construct nuclear powered submarine. The biggest task of all is to secure the enriched uranium. Accordingly, this research is about the way of enriching and securing the nuclear fuel that are used in the nuclear submarine with the characteristics, merits and demerits of the nuclear submarine. Due to the fact that the pressurized water reactor in South Korea is the reactor that was originally built for the development of nuclear powered submarine, many parts is designed to be suitable for the submarine propulsion. However, in order to apply this to submarine it is needed to consider additional requests such as the position of reactor, accident-coping system, radioactive covering, reactor output adjustment and ship's pitch and roll in order to apply this to submarine. Nuclear submarines have much higher speed based on the powerful propulsion in comparison with diesel-electric submarine and also have bigger loading area. Besides, there is no need to snorkel and they also have advantages in covertness with the multi-noise proof system. The nuclear technology in South Korea has seen the dramatic development since 1962 and in 1998 reached to the level that we have succeeded in the localization of nuclear plant and exported the world-class one-piece small-sized reactor (SMART) to UAE. To operate these reactors, we import the whole quantity of low-enriched uranium and having our own uranium enrich facility is not probable because of the budget and international regulations. With the ROK/US nuclear agreement revised on 2015 November, the enrichment of uranium that are available without special permission has changed up to 20%. According to the assumption that we use the 20% enrichment of Uranium on U.S. virginia class submarine, it is necessary to change the fuel after 11 years and it will cause additional cost of 1 billion dollars. But the replace period by the uranium's enrichment rate is not fixed so that it is possible to change according to the design of reactor. Therefore, I would like to make a suggestion on two types of design concepts of nuclear submarine that can be operated for 30 years without nuclear fuel change by using the 20% enriched uranium from ONNp.First of all, it is possible by increasing the size of reactor by 3 times and it results in the 1,000t increase of the weight. And secondly, it is by designing the one piece reactor to insert devices such as steam turbine, condenser into the inside of nuclear core like the Rubis class submarines of France.

The aim of this study is to find ways to apply the strategic communications to the Republic of Korea Navy. It may be a little bit late for the ROK Navy to accommodate the SC in these days because the adoption and implementation of the SC by the Combined Forces Command has already been begun. It was in 2007 when the SC was in place in the CFC. ROK's Ministry of National Defense and Joint Chiefs of Staff have also mulled over the SC and begun to apply it in part in the annual exercises such as Key Resolve command post drills and Foal Eagle field training exercise, etc. For the ROK Navy, in addition to those exercises, it is faced with further areas like North Korean maritime provocations and other maritime incidents where its version of SC is needed. As noted, the SC is not intended to deter or defend directly those provocations and incidents, but aims to create conditions favorable to the achievement of the navy's strategic objectives. The ROK Navy has to establish a SC planning center and implementing organizations within the Headquarters to be consistent with its above organizations such as MND, JCS, and CFC that have already applied the SC in part or in entirety. SC center and other related organizations need to be under the control of VCNO and the center needs to be located and administered by the policy division in N-5 at the HQs. The vision of the navy's SC is the winning without combats and the least damages in time of war. In other for the navy to reach the vision, the strategies to be executed are early establishment of SC implementing organizations, forming consensus over the need for the SC within the navy, strengthening core competencies to apply the SC, acquiring the SC experts and making doctrines on the SC. The SC, in addition, in the navy has to be planned and implemented in not only peace time and crisis time but also war time.

북한의 SLBM 위협이 대한민국 안보에 미치는 영향에 대해 그동안 많은 논의가 있어 왔지만, 북의 잠수함에서 발사하는 탄도미사일이 보유한 진정한 위협에 대한 인식은 아직도 부족한 듯하다. 그 이유는 대부분의 논의가 북 SLBM 기술의 성숙도와 완성시기 등 기술적 수준에 관심이 치우쳐져 있기 때문이다. 핵전략과 억제전략의 관점에서 본다면 북한의 SLBM 개발은 한미동맹의 제1격에 대한 완벽한 제2격 능력 보유에 그 핵심이 있다. 즉 향후 개발될 북한의 SLBM은 평양 김정은 정권의 생존을 보장할 직접적이고 핵심적인 전력이 될 것이다. 이는 궁극적으로 한미 군사동맹과 북한의 현 군사력 균형을 깨뜨리고 앞으로 북의 군사도발 가능성을 더욱 높이는 결과를 가지고 올 것이다. 북의 핵전략은 현재 확증보복(assured retaliation) 단계로 발전하고 있으며, 결국에는 전쟁에 사용될 전술적 핵무기 능력(war-fighting capability)을 갖게 될 것이다. 이에 대한민국 해군은 우리의 강점을 활용하여 적의 약점을 공략할 수 있는 상쇄전략(offset strategy)을 개발하여야 한다. 북한의 현 제한된 잠수함 기술력과 대잠작전 능력을 고려할 때 한국해군은 수중영역에서의 공세적 대잠전(offensive ASW) 개념을 보다 발전시켜야만 할 것이다. 이는 미 해군이 냉전기간 중 소련해군 핵추진전략잠수함(SSBN) 대응을 위해 발전시킨 전략대잠전(strategic ASW) 개념에서 교훈을 얻을 수 있다. 미 해군은 소련 해군의 SSBN 을 억제하기 위해 공세적인 전략대잠전을 수행했고 그 결과 소련해군은 자국의 연안에서 벗어나지 못하는 요새전략(bastion strategy)를 추구할 수밖에 없었다. 당시 미 해군의 전략대잠전은 공격잠수함(SSN), 대잠초계기, 수중 탐지체계(SOSUS), 공격기뢰 등의 전력으로 구성되었다. 따라서 북한 SLBM 에 대한 한국해군의 전략개념은 북의 핵전략(제 2 격능력)을 억제하는 방향으로 정립되어야 하며, 이를 위한 해군력 건설은 대잠전 능력 강화에 초점을 맞추어야 한다. 우리 해군은 장기적으로 핵추진잠수함을 비롯하여 성능이 향상된 대잠초계기, 한반도 해역을 중심으로 한 미 해군의 SOSUS 와 유사한 수중탐지장비 그리고 장시간 수중작전이 가능한 무인잠수정(UUV)을 도입해야만 한다. 단기적으로는 현재 추진되고 있는KAMD 체계에 SM-3 를 보유한 이지스함을 포함시켜, 북 SLBM 에 대한 요격능력을 강화해야 할 것이다. 한미동맹은 북 핵전략의 핵심전력인 SLBM 개발에 대한 위협인식을 공유해야만 하다. 작전적 수준에서는 양국 해군 간 대잠전 및 대유도탄전 작전운용성 증대에 우선순위를 두고, 기존의 한미 간 연합작전능력 강화뿐 아니라 위기시를 대비하여 미일 간 구축되어 있는 대잠전 및 대유도탄전 능력도 활용할 필요가 있을 것이다.