As a doctrine concerning the acquisition of territorial sovereignty, the theory of historical consolidation on the one hand faces some disputes in the sphere of application, and it is regarded by some scholars as a “supplementary consideration” or a “non-independent source of territorial sovereignty” in the establishment of territorial sovereignty. On the other hand, the theory emphasizes that on certain circumstances,the establishment of territorial sovereignty is a progressive process in which multiple factors play an integrated role. It focuses on the publicity of the territorial claims of the state, the adequacy of sovereignty declaration action, the interests of countries concerned, the recognition or acquiescence of other countries and the international community, and estoppels, in order to determine whether the cumulative effect of multiple factors or “multiple grounds” is sufficient to establish territorial sovereignty. The analytical approach has a certain impact on international justice and the practice of state behavior. Therefore, we should pay attention to the analytical method of “historical consolidation theory” in the settlement of territorial disputes.

Developing countries are important forces in promoting the construction of new international political order and the growth of the global economy. Owing to the common interests and the coexistence of destiny, China has always attached great importance to strengthening the cooperation with developing coun tries. However, there are more than 160 developing countries in the world, and their political systems and the situations are so different that can it lead to their divergence of interest, which to a certain extent, will inevitably reduce the actual efficiency of the cooperation between. Middle powers are geographic important and have a relatively large population of a higher status among the developing countries, which have important symbolic influence. Taking middle power as focus and main emphasis concerning China's national diplomacy with developing countries could help promote the concentration level and effectiveness of Chinese diplomacy. The article will explore that how China could take the middle powers as the strategy support to promote the relation with developing countries, with focus on strategies, countermeasures, mechanisms, and future direction, which will further enrich and improve the effective policies and strategies of Chinese diplomacy with developing countries.

In recent years, China, Russia and the United States have respectively proposed their strategies concerning Central Asia. Russia and the United States seek to consolidate their position in Central Asia. In the Belt and Road Initiative, the Central Asian region has been incorporated into the “Silk Road Economic Belt”. The situation of strategic overlap and conflict among the three countries has thus been formed. Based on the power transition theory, a thorough analysis of the circumstance reveals that, after the Cold War, the Central Asian region has experienced three stages: power vacuum, competition between the US and Russia, and a scalene triangle relationship among China, Russia and the US, which objectively shaped the fact that the power is being transferred. Strategies of China, Russia and the US concerning this region have overlapped in various aspects, but it is quite different in both strategic intent and its implementation. Although China has no intention to participate in the Central Asian hegemony, the development of China's national strength and strategic vision will lead to the increase of China􀆳s power and influence in the region.

At present, In the shifting process of global climate and energy pattern, the countries are confronted with much stricter constraints on carbon emissions. One country's capacities to deal with and make a break-through of carbon constraints determine its position in the international order transition.  Clean energy, as the leading factor of the next generation energy system, provides an integrated solution for the response to climate change, energy security and low-carbon transition. In such a context, the development of clean energy diplomacy has become an important focus of a country to guarantee the favorable international environment for its domestic energy transformation and promote the construction of a new order of global governance of climate and energy. With the rapid development of clean energy, China's clean energy diplomacy has undergone a four-stage evolution from “the exogenous capacity construction” to “the endogenous institutionalization”. Especially in the post crisis era, when China has become a leading clean energy country, its diplomacy present so their new trends such as multi-level and multi-track, “south-south” innovation model, and global networking partnership. The domestic green development, the systematic power flowing and China's diplomatic strategy shifting constitute key dynamic factors behind the transitional process. The new tendency will help China keep a dominant position in the international transition towards a low-carbon pattern, while improve China's discourse leadership and institutional power in the construction of a new global order of climate and energy.

Although there are some differences concerning the literal expression of Tsai Ing⁃wen administration's South China Sea policies before and after, its core policies have not been changed, which are sticking to Taiping Island, seeking refuge in the United States and utilizing the South China Sea issue to carry out “Taiwan Independence”. Tsai Ing⁃wen's policies on the South China Sea are not only distinct from that of Ma Yingjeou, but also with Chen Shuibian administration who also advocated “Taiwan independence”. Identifying the essence of Tsai Ing⁃wen's policies on the South China Sea will be conducive to clarify its impact on cross⁃strait relations. Furthermore, it helps us make appropriate policy choices in future work with Taiwan concerning the South China Sea.

From the late 19th century to the early 20th century, America has realized its strategic rise as a sea power. There are many similarities between the marine geopolitical situations that US ever faced during that time and what China confronts in the South China Sea at present. In the 19th century, the question of how to realize the emergence as a sea power drove Mahan to study the Caribbean Sea power, and the dredge of the Panama Canal was the external stimuli to the emphasized importance of the Caribbean Sea. Then Britain⁃America ties fuel further tension as the so⁃called Thucydides trap. However, the development of history showed that America rose smoothly without the war. China faces a similar situation now, but China would never do the same things as America did in the 19th century. While avoiding risks and taking the opportunity, China should decide carefully and act effectively to realize strategic rise in the sea.

The Five Power Defence Arrangements (FPDA) is unique to Southeast Asian regional security instrument. The FPDA was initially conceived as a transitional agreement to provide for the defence of peninsula Malaysia and Singapore. With the constantly changing security situation in the Southeast Asia, the FPDA has developed a sophisticated organizational mechanism and comprehensive exercise programme. These updates has undoubtedly enhanced military professionalism, interoperability and operational capability, which has effectively ensured the security of the South China Sea lanes. Meanwhile, FPDA and other regional security cooperation mechanisms are mutually reinforcing. The practice of the FPDA to pioneer the use of military security tools to achieve non⁃traditional security objectives has provided a positive example of security cooperation among all countries in the waters of Southeast Asia. As a result, the FPDA has made a positive contribution to safeguarding the navigation security, especially in dealing with non⁃traditional security issues.

Canada's historical title claim to Arctic Archipelago constitutes its important state practice in international law. There are two mainlines underpinning such a claim, among which are historical title in the law of the sea and in the law of territory respectively. The former indicates exercising of sovereign authority through legislation and acquiescence of other states. The latter focus on the aboriginal people transferring Arctic territory, such as land, water and ice-covered areas to Canada and its succession of aboriginal people's practice of occupying. The article concludes that the former has its flaws while the latter establishes historical title, which enables us to attach importance to particular state practices and its influence on the development of international law.

As the Chinese economy went into the phase of the “new normal”, China's economic diplomacy accordingly entered the “new normal” stage. Nevertheless, China's economic diplomacy in the context of “new normal” inherited its original content and strategic objectives, and demonstrated a unique connotation and innovation. China's economic diplomacy in the context of “new normal” emphasizes the “leading” position of China in the global economy, and serve for domestic economic development at a higher level. Meanwhile, it adheres to a diversified implementation to expand the routes of economic cooperation. Based on this, it has accumulated new advantages and new motives, and it provided more and abundant public goods that are beneficial for promoting the reform of the global economic governance system. In the future, China's economic diplomacy should solve two key issues as soon as possible. That is, how to further enhance its own effectiveness, and how to transform the powerful economic influence into practical political influence?