Geopolitics or Political Geography is an essential academic field that should be studied carefully for a more comprehensive analysis of international security relations. However, because of its tarnished image as an ideology that supported the NAZI German expansion and aggression, geopolitics has not been regarded as a pure academic field and was rejected and expelled from the academic communities starting from the Cold War years in 1945. During the Cold War, ideology, rather than geography, was considered more important in conducting and analyzing international relations. However, after the end of the Cold War and with the beginning of a new era in which territorial and religious confrontations are taking place among nations - including sub national tribal political organizations such as the Al Quaeda and other terrorist organizations - geopolitical analysis again is in vogue among the scholars and analysts on international security affairs. Most of the conflicts in international relations that is occurring now in the post-Cold War years can be explained more effectively with geopolitical concepts. The post - Cold War international relations among East Asian countries are especially better explained with geopolitical concepts. Unlike Europe, where peaceful development took place after the Cold War, China, Japan, Korea, the United States, Taiwan and Vietnam are feeling more insecure in the post-Cold War years. Most of the East Asian nations' economies have burgeoned during the Cold War years under the protection of the international security structure provided by the two superpowers. However, after the Cold War years, the international security structure has not been stable in East Asia and thus most of the East Asian nations began to build up stronger military forces of their own. Because most of the East Asian nations' national security and economy depend on the oceans, these nations desire to obtain more powerful navies and try to occupy islands, islets, or even rocks that may seem like a strategic asset for their economy and security. In this regard, the western Pacific Ocean is becoming a place of confrontation among the East Asian nations. As Robert Kaplan, an eminent international analyst, mentioned, East Asia is a Seascape while Europe is a Landscape. The possibility of international conflict on the waters of East Asia is higher than in any other period in East Asia's international history.

In 1996, China, Japan and the ROK all became the party to the 1982 United Nations Convention on the Law of the Sea (UNCLOS). Since then, the UNCLOS has been a fundamental basis for the resolution and management of maritime disputes amongst them. However, there still remain acrimonious disputes in the region. Resources nationalism and the revival of geopolitics aggravates the disputes particularly on sovereignty over disputed islands, maritime delimitation and the legal nature of military activities in other States' Exclusive Economic Zones. Under the circumstances, why have the demands for the conclusion of a regional agreement been raised in this region? A desirable regional agreement regarding ocean affairs should be compatible with the rights and obligations under the UNCLOS, a universal norm regarding ocean affairs. This paper will propose a desirable regional agreement by adopting an incremental approach.

A Paradigm shift is in process in China's foreign policies during Xi Jinping's era. Such changes occur with changing national identities from developing country to great power, and from continental power to continental-maritime power. China's pursuit for sea power embraces its global strategy. Accommodating the new identity of maritime power, China is developing its maritime strategy. New silk-road strategy actively utilizes China's advantage in economy, while avoiding direct military challenges against the U.S. China seeks an associated balance of power with the U.S. On the other hand, China make its determination clear to protect its core national interests, particularly Taiwan straits issue, deploying Anti-Access and Area-Denial strategy. 'Pax-Americana 3.0' and 'China's rise 2.0' have convoluted and evolved in complexity. South Korea faces much tougher challenges ahead in its foreign and security environments.

The Asia-Pacific Region has emerged as a arena of geopolitical competition between the U.S. and China. The Obama administration of the U.S. had laid out the concept of rebalancing strategy toward the region, concentrating its 60 percent of Naval Forces to the region till 2020 and consolidating its network of allies and partners. Whereas Chinese leader Xi Jinping also put forward the concept of new type of major power relations concerning its relations with the U.S. and a concept of 'the Asian Community of Common Destiny' aiming at a more intensified mutual relation among countries in the region. In doing so, Asia-Pacific region gradually became the arena where mutual competition and cooperation between the U.S. and China has crossfired. As a close ally to the U.S. and a partner to Japan, South Korea should develop trilateral naval cooperation by holding joint naval drill with the aim of humanitarian support and disaster relief. At the same time, Seoul also should make efforts to proceed mutual confidence building with Beijing by deepening military-to-military cooperation. These policy options will be helpful to enhance Seoul's security posture in the region.

This paper will examine some past and current issues concerning the Republic of Korea's national strategy, focusing predominantly upon how the ROK should respond to the urgent maritime-oriented strategy highlighted by the recent developments and achievements of national prosperity achieved during last three decades and identify some of successful cases in East Asia. Some consideration will also be given to more general emergent issues of trends and developments of East Asian countries which might affect to define the ROK's future national strategy in the context of its national grand strategy to enhance national interests and prosperity. ROK is especially dependent upon open Sea Lanes of Communication (SLOC) and its national security emphasizes the sea as the medium of geopolitical and geo-economic development, given the sea known as core geographic option remains that ROK is an important maritime power, ranking the world-level nation in term of GDP, sea-borne trade, container processing capability, shipbuilding capacity and so on. It should be apparent, therefore, that ROK's national strategic development depends upon the relationship between its peninsula geography and its national development based on sea-borne economic growth and its maritime-oriented future national strategy will be the best option to maintain its national development and economic prosperity.

This thesis analyzes Somali piracy as a non-traditional threat to the Sea Lines of Communication (SLOC) and international countermeasures to the piracy. In an era of globally interdependent economies, the protection of sea lines and freedom of navigation are prerequisites for the development of states. Since the post-Cold War began in the early 1990s, ocean piracy has emerged as a significant threat to international trade. For instance, in the Malacca Strait which carries 30 percent of the world's trade volume, losses from failed shipping, insurance, plus other subsequent damages were enormous. Until the mid-2000s, navies and coast guards from Malaysia, Indonesia, Singapore, together with the International Maritime Organization (IMO), conducted anti-piracy operations in the Strait of Malacca. The combined efforts of these three maritime states, through information sharing and with reinforced assets including warships and patrol aircrafts, have successfully made a dent to lower incidents of piracy. Likewise, the United Nations' authorization of multinational forces to operate in Somali waters has pushed interdiction efforts including patrol and escort flotilla support. This along with self-reinforced security measures has successfully helped lower piracy from 75 incidents in 2012 to 15 in 2013. As illustrated, Somali piracy is a direct security threat to the international community and the SLOC which calls for global peacekeeping as a countermeasure. Reconstructing the economy and society to support public safety and stability should be the priority solution. Emphasis should be placed on restoring public peace and jurisdiction for control of piracy as a primary countermeasure.

The Republic of Korea navy challenged from the unexpected surprise attacks by the North Korea navy, albeit, the developments of up-to-date naval forces' technology, and the ceaseless efforts for war preparedness. My study divided into two categories. Qualitative methods used for literature review of international relations theory related to the war onset and for investigating events occurred on the Peninsula and its surrounding seas from 1968 to 2007. Quantitative method used such as the analyses of national power index of the two Koreas, the United States, and China, the uses of equation model to calculate power index of alliance, COPDAB(Conflict and Peace Data Bank) index analysis. Like Choi's study on East Asia maritime conflict, as a conclusion, considering both AT theory and maritime national power as a tool for predicting maritime conflict in the Peninsula proved significant. Based on the study, ROK navy need to prepare for the maritime conflict because the results showed North Korea would initiate maritime disputes sooner or later using fatal asymmetric forces and methods. As a policy suggestion, we are required to maintain a concrete ROK-US alliance ties and to construct naval forces due to the deterring functions of maritime national power.

Jeong YagYong, who are the SilHak Scholar during 18^th to 19^th century, wrote the Sadaegore with his pupil Lee Cheong. This work is the guide of diplomacy, which are asked to write from King Jeongjo. Although this book was completed after King Jeongjo's death, it harbors the King's thoughts about diplomacy or the relationship with China. Haebanggo, one chapter of the book, is about marine policy and how to treat the castaways. In this chapter, Jeong YagYong provides various ways to deal with these problems in marine area and sea refugee I will examine the Jeong YagYong's thought about the problems and ways to address these problems. Futhermore, I will inquire Jeong's opinion on the boundary in marine area. He recognized that many border transgressions happened in marine area at that time and considered that as urgent political affairs. Haebanggo consists of two parts. First part of the book is about protect own island from other countries. The rest part is about cases of dealing with castaways and their transgression. I argue that Jeong YagYong intended to make distinct borderlines in marine area and empathized the necessity of protecting Joseon's islands from other countries.

최근 몇 년 동안 나타난 러시아 해군의 부활(resurgence)은 우크라이나 사태로 본 러시아 군사력 증강을 대표하는 상징이다. 전통적으로 러시아 해양전략(Sea power)은 러시아 경제 및 안보 목표를 달성하는데 있어 핵심이었다. 러시아 해군은 주로 전략적 억제, 연안방어, 해상교통로 보호, 해외전개 그리고 군사력 투사 등의 임무를 수행한다. 특히 최근 들어 러시아 해군력이 양적 질적으로 증강되는 양상을 보이고 있으며, 이는 최근 잠수함, 수상함 그리고 해군항공 전력이 크게 증강되고 있는 현상에서 증명되고 있다. 이는 불과 몇 년 전까지 러시아 해군력에 대한 정비 및 작전 운용에 있어 많은 문제점을 보이던 부정적 사례와 현격히 다른 모습이다. 특히 푸틴 정부에 들어서 러시아 해군은 양적이며 질적인 증강뿐만이 아닌, 세계 해양에서의 원해 해군작전을 비록 지금은 간헐적이기는 하지만 활발히 실시하고 있으며, 러시아 주변국 해군과의 다양한 해군협력도 추진하고 있다. 궁극적으로 러시아 해군은 단기적으로 연안방어를 기본 임무로 수행할 것이나, 장기적으로는 과거 구소련 해군력 위상과 영향력을 부활시키기 위해 세계 무대에서의 군사적 영향력을 증진시키는 대양해군(Blue Water Navy)을 지향할 것이다.