Alliance and Anti -League is the enduring theme in international politics。Under the national national system，Cooperation and resistance in the Alliance，Competition and confrontation between the alliance，is the most common communication mode。The alliance and re -association process of major powers，Sometimes it can maintain the balance of the relationship between each other，Sometimes it will lead to the upgrade of regional and international conflicts，To a large extent, the basic direction of international relations has been shaped。Alliance politics is both a mature research field in international security branches，Given a rich theoretical accumulation，It also needs to face the new facts provided by international political changes and improve it。

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In the field of international security，Alliance is a basic way to carry out security cooperation between the country。The country that concluded the alliance determined the security obligations that they afforded with each other in a formal or informal agreement，Coordinated participants provide support and respond to third -party behaviors when facing specific security situations。According to the differences in the content of the commitment，Alliance participants guarantee military support to resist third parties，or maintain at least neutral，or negotiation。

Alliance based on clear military security obligations and commitments，So，Coping security threat is the Bet365 app download most basic function of the league，Whether there is a commitment to provide security guarantee is also the main sign of other forms of security cooperation。The promise of the alliance may be secret、Oral，It may also be public、Written。The formation and maintenance of the alliance does not depend on the specific institutional form。Before World War II，The institutionalization of the alliance is generally very low，More strategic coordination and joint operations reflected in peacetime。After World War II，The United States led alliance system is high institutional，But there is also a big difference with the specific forms of different regions and countries。

Alliance can make up for a country's ability to simply rely on its own forces to ensure security，Shining the strength gap relative to the opponent，or reduce the number of opponents needed to face，in order to concentrate on cope with the main threats。At the same time，Because the alliance is clear or potential for third parties，The conclusion and survival of the alliance will inevitably cause tension or even confrontation with countries outside the alliance。Of course，In addition to implementing security functions，Alliance can also significantly enhance the strategic coordination of allies on more extensive issues，Take a consistent position when dealing with each other's concerns。In the asymmetric alliance with a large strength gap，The leading parliament occupying the leading position is to provide safety protection as a condition，In exchange for the obedience of the small and medium -sized allies for it，Provide support for the area or global strategy。

　Agenda research by the alliance

The security interaction bet365 Play online games between the alliance and the country is closely intertwined，So that most issues in the international security field cannot be discussed separately from the alliance mode。As a more mature field，Alliance political research involves three major aspects。

First，The power of the alliance phenomenon itself。Same as any form of political organization，Alliance has its formation、Keep、The complete cycle of change and disintegration。Safety demand is both the basic function of the league，It is also the main motivation that leads to staged changes in the life cycle。Common and urgent security threats make ideology、A cooperation between countries with different social systems and cultural traditions，can also allow the enemy to surpass the difference，Maintaining alliance relations in a short or long -lasting manner。At the same time，We also see，Even when the common security threat still exists，Alliance relations will also rupture。The process of exploring the development and evolution of the alliance，Exploring it、Inner logic of duration and decline，is the most classic issue of alliance politics。

Second，Alliance and national behavior。The choice between forming alliances and not alliance is itself a strategic behavior。If a country chooses alliances，Will face the timing of alliance、Objects and types such as different considerations。Once the alliance is formed，You need to consider how to operate and manage。For the inner，Alliance needs to increase the strength of military cooperation，in training、Information、Logistics、Battle and other fields to strengthen cooperation。Look outside，It is also necessary to avoid the bet365 Play online games risk of involving the conflict。Share responsibility、Equipment of each other、deterrent opponents，These contradictions and conflicts have increased the difficulty of alliance management，It also makes the interactive mode between the country more complicated。Even if a country pursues the policy of not alliance in the security,，Also facing a question of how to deal with the pressure of a hostile alliance，Demand for internal checks and balances and differentiation of the opponent alliance。

third，International political consequences caused by the alliance。Alliance and War、Conflict、Crisis and other important international phenomena are linked，Its influence is prominently reflected in the role played in major international security incidents。Important international war since the 20th century，Including the two global wars of World War I and World War II and the Gulf War and other regional sexual war，All alliances against the war against another league (country)，There are only a small part of the other international conflicts that are performed between two countries。Enter the 21st century，Alliance is still in the core position in the competition of large countries。The United States Leadership Alliance implemented Afghanistan、Iraq、Libya and other military invasion operations。The continuous expansion of NATO has triggered the recent Russian -Ukraine military conflict。

　　Expansion space of political research of alliance

Over the past few decades，Academic circles have discussed the main issues involved in alliance politics，Rich and expanded our power to the alliance from different theoretical paradigms and research bet365 Play online games paths、Research on the Influence of the Alliance and Alliance。Of course，In a new background，There is also the following direction that can be expanded。

First，The scope of enrich the alliance experience case。Existing research mainly relies on the alliance in the European multi -polar system (especially before World War I)，and the United States alliance system after World War II to start theoretical construction，There are outstanding problems with limited experience in existence。Although the international system today，No other competitive alliance appears，But there have been many national alliance phenomena in different regions。incorporate more historical cases in，Case sets that can expand experience inspection，helps to test and correct many existing theoretical assertions。

Second，Inspection of the conversion bet365 Play online games between the alliance and other security cooperation behaviors。Current，The form of security cooperation between the country is diverse，In addition to the alliance based on the clear security commitment, there is still existence，Security mechanism、Joint Front and Security Partnership, etc. It is also common in the security architecture of different regions。Even the United States has many formal allies，It is also increasingly inclined to carry out safety cooperation in the form of bilateral or multilateral security partnerships。Safety partnership does not mean that it is completely out of the traditional alliance category，To a large extent, it is based on existing alliances to carry out more collaborative cooperation in specific fields。Examine the preferences and weighing of these forms of security cooperation，Bet365 app download It can better understand that the country takes different strategic choices with the changes in the national security environment。

third，Follow the energy of SMEs in the league。Existing research mainly focuses on World War I.、The process formed by the Alliance for World War II and the Cold War，More emphasis on the motivation and dominant role of the alliance in the league alliance。Actually，Small and medium -sized countries usually use the space provided by the competition and confrontation，Strive for certain autonomy in the alliance。During the Alliance's maintenance process，Small and medium -sized countries will bear the defense responsibility、Provide issues such as providing military support and coordination of policy positions.。These interactive processes make the internal relationships of the alliance present a large change，It has restricted the effectiveness of the great country's influence of the small and medium -sized national strategy。

Fourth，Alliance's extension effect and limit in the non -safety field。With the competition of great powers, it is more presented in the form of non -war，Because of the correlation between economy and security, it becomes closer，The strategic coordination function of the Alliance is continuously expanded in areas other than security，In technology competition、Supply Chain and Maritime Security, which involves the strategic competition involved in the strategic competition, is particularly obvious。Build barriers in the high -tech field，Global Supply Chain of the key industry of reorganization，Frequent economic sanctions and compulsory means，These measures depend on the participation and cooperation bet365 live casino games of allies。The extension effect of the alliance makes the interaction form inside and outside the alliance richer，But it is also necessary to notice that the coordination effect in the non -security field is largely limited by security concerns and benefits。

　(The author is a professor at the Department of International Relations of Tsinghua University)