Currently, the UN General Assembly has officially initiated the process of developing an international legally binding instrument on the conservation and sustainable use of biodiversity beyond national jurisdiction. Regarded as the third implementing agreement of the United Nations Convention on the Law of the Sea, the instrument will cope with a series of important issues including high seas marine protected areas. In the earlier negotiation, the parties have not reached a consensus on the management model of the high seas protected areas. Based on an indepth analysis of both global and regional management model, limitations of the regional model on the issue of high seas marine protected areas could be concluded. In the followup negotiations, China should put forward corresponding measures on the basis of insisting on advocating the adoption of a global model so as to effectively promote negotiation on the issue of high seas marine protected areas.

The US has proposed and started to implement the “free and open Indo⁃Pacific strategy”, which will have a profound impact on the regional situation, especially the South China Sea issue. It is of great significance for China to pay high attention to the developments of the US’ strategy and the US⁃Vietnam relations, in order to ensure a secure environment, strengthen the relationship with ASEAN and safeguard the country's important period of strategic opportunity. In recent years, both Vietnam and the US have attached great importance to the bilateral ties. The US has enhanced bilateral political, economic and security cooperation, which revealed its strategic intention to shape Vietnam into an important partner to counterbalance China. Also, both countries share the intention to collaborate to contain China concerning the South China Sea issue. The US intends to upgrade the bilateral relationship, invite Vietnam to join the Quadrilateral Security Dialogue, enhance military interaction to deter Chinese actions in the South China Sea, etc. However, Vietnam has to take into account ASEAN's concern about the US Indo⁃Pacific strategy. The country will continue to rely on the US support to deal with the South China Sea issue, albeit in a low⁃key manner. Vietnam does not want to commit itself to a rigid anti⁃China bloc or to adopt an openly confrontational approach in dealing with China. In nature, the country will not support the US strategy at the cost of its own national interests.

Since Japan’s diplomacy towards the South Pacific island countries has completed a critical transformation, both its diplomatic orientation and behavior need to be further discussed. After World War II,Japan once completely withdrew its influence from the South Pacific region. With the rapid development of Japan‘s economy after World War II and the establishment of the Pacific Islands Forum, Japan has resumed its effort to positively enhance diplomatic ties with the South Pacific island countries since the 1980s. By then, Japan has successfully hosted eight consecutive Japan⁃Pacific Islands Summits, which has transformed its diplomatic logic from environmental diplomacy to marine diplomacy in the South Pacific region. Influenced by dual factors of historical inertia and realistic diplomacy, Japan strives to shape a diplomatic model in accordance with its own interests and preferences in the South Pacific region. At present, Japan has upgraded its South Pacific island diplomacy, as the strategic “east wing”, to the position that is paralleled in significance with the Middle East and Africa, which are the “west wing” of its marine strategy.In the future, China’s diplomacy in the South Pacific region will have to directly respond to Japan‘s marine strategy, and engage in the strategic game with it.

China has conducted three struggles for safeguarding rights in the South China Sea (SCS) since 2012, which demonstrated the policy of “sovereignty of SCS islands belongs to China” in the new era. The specific goals and effects of the three struggles for safeguarding rights in the SCS were different in different situations, but they shared the following characters: limited goals, various and complementary means, and the firm will, which resulted in a very complicated process to safeguard rights. From a more comprehensive and coherent perspective, the three conflicts to defend rights of the SCS responded to specific situations in the SCS which aimed to realize specific objectives. In conclusion, based on the tenet to maintain China's domination and participation in the SCS situation, measures to safeguard rights in the SCS are supposed to serve the grand strategy of peaceful development, and attention should be attached to the construction of both hard and soft power.

Much research has been done on alliance and alliance commitment, but little has addressed the question that under what conditions will a nation intervene in the dispute over territory and sovereignty between its alliance with a third party. In fact, the existence of alliance relations is not the prerequisite that a nation will assist its ally in a territorial dispute. The nation's willingness of intervention and degree of involvement are subject to three factors: alliance obligation, benefits from the intervention, and risks of alliance entanglement. These differences explain why the US officially claimed that the US⁃Japan Treaty of Mutual Cooperation and Security applies to dispute over Diaoyu Islands, while refuses to provide its defense commitment to the Philippines when it comes to the South China Sea. Although we should not exaggerate the alliance's deterrence effect on territorial disputes, we need bear in mind that the US's unneutral intervention would only intensify regional disputes in East Asia and aggravate the complexity to a peaceful settlement.

The South China Sea has been one of the most significant issues in Sino⁃US relations, regional security and even the evolution of global geopolitics. Since directly intervening the given issue in the middle 1990s, the US's policy on the South China Sea has experienced different stages, from policy declaration, diplomatic involvement to military intervention. The basic logic of the US policy builds on the so⁃called strategy of “defending the national interest and international norms”, “maintaining regional military balance” and “strengthening the US's primacy in the region”. After the presidential inauguration, the Trump administration's policy on the South China Sea is shaped by the mixed strategy of containment and offset.Based on radically and stubbornly using military and diplomatic tools, it has become a component to respond to the “strategic competition of great powers”, which increasingly influenced Sino⁃US relations and regional security. China's strategy on the region should focus on the changing circumstance, make full use of various measures, and effectively meet growingly serious challenges in this strategic direction.

The importance of the multilateral trading system to the world economy and trade is self-evident.Since the outbreak of the global financial crisis in 2008, the US, once an initiator of the multilateral free trade system, has begun to move toward the opposite of free trade. The fundamental reason lies in the law of imbalanced development of capitalist economy, which fundamentally restricts the implementation of free trade policy. Changes in the multilateral trading system will inevitably have a major impact on the development of the Asia-Pacific economic and trade integration. With reference to the development history of the Free Trade Area of the Asia-Pacific (FTAAP), it is noted that in pursuit of common interests, the driving force for cooperation in providing regional economic public goods will be even greater when there are economic motivation and commercial interests. In the process, China􀆳s growing economic ties with economies within and outside the region determine that China will play an important role and make efforts to provide regional public goods in the construction of the cooperation mechanism in the framework of FTAAP.

In the process of jointly building the “Polar Silk Road”, there is an interest game between China and Russia. Based on the subjective game theory, the authors make an analysis of the game from both shortterm and long⁃term perspectives. In the short run, jointly building is the dominant strategy for both countries, so cooperation and jointly building the “Polar Silk Road” is bound to be the equilibrium of the game.In the long term, changes in external conditions and endogenous accumulations of the game will make a difference to the strategic choice of Russia. Therefore, Russia may deviate from the short⁃term game equilibrium, which could damage China's investments in building the “Polar Silk Road”. According to the analysis, the authors further propose that China should coordinate policy with Russia, focus on interests of cooperation between Russia and China, and implement strategies of staged investment and enhancing cultural exchanges to ensure that Russian does not deviate from the short⁃term game equilibrium in the long⁃term game, so as to safeguard the long⁃term interests of China in jointly building the “Polar Silk Road”.