Sovereignty is a notion that a government of a certain nation is free to act as it desires within its own territory. it is the ultimate authority or overseer in all decision-making processes of a state in its maintenance of an orderly society. This is the premise of he peaceful coexistence amongst states with differing political systems.
Power, in international relations, describes the ability of an actor to exercise certain levels of influence over another actor within an international system. It is therefore the ability to direct actions and decisions of others. More comprehensively, power is the production of effects influencing and shaping the capacities of actors in the determination of their fate and circumstances.
In the context of international relations, balance of power differs from hegemony in a number of ways. Balance of power is a policy and posture of a country of a group of countries protecting themselves against other nation(s) by matching power against that on the opposing side. Hegemony is all about ruling and leadership. It is the ability of actors with overwhelming capacities to influence and shape the global system through often coercive or non-coercive means. Therefore, the differences are built along the lines of formality and social life where power deals with effectiveness and hegemony is all about creating influence, authority, and domination over others. Balance of power aims to achieve effectiveness in the relationship between international players while hegemony intends to generate dominance over an international group or country.
Professor Fred Halliday defines international relations from a point of view of diplomacy and war, authority and sovereignty, and international law. He sees international relations as an amalgamation of perspectives and theoretical models that aim to explain the world in relation to salience and dominance of states. He also includes the role of non-states in the running of the world and in defining the relationship of nations and groups of nations. Therefore, beyond the basic definition of international relations as the interactions between two or more nations in the context of the cultural, political, and economic ties, Halliday would add the role of other actors including non-state actors, the military, and the role of dominance, war, sovereignty, balance of power and so on.
The international society is said to be anarchic and not chaotic. In neorealism, the international system is permanently anarchic due to the conspicuous absence of an overseeing superior authority. Additionally, the international society lacks a basic sovereign structure or a supreme authority. In anarchic structures, there lacks coercive and superior powers to resolve disputes, enforce order and the law. However, the international society is not chaotic. Chaotic systems are unpredictable, have circular causality, and are difficult to model. The international society lacks a supreme authority, yet is predictable, easy to model, and has a system to ensures its continuous existence.
Countries such as Canada, Venezuela, Brazil, and Mexico are termed as 2nd tier powers because they do not fall amongst the most successful, largest economies, or having the most important aspects of power in comparison to larger nations like China and the United States. The simple definition of 2nd tier power is that it is not first rated. 2nd tier powers do not have the power to rule such as the United States does through a hegemony structure. However, they have the capability to help shape important policies and define relationships with the tier 1 powers.
The US has equally interfered and defended the sovereignty of its neighbors through influencing international policies. For example, its activities in Cuba and in Venezuela have meant that it has influenced the direction of the political and economic directions of the nations. More recently, its war on drugs has meant strained relations with Mexico including both defending the neighbor and interfering in its ability to run the country effectively. The United States has interfered in the political events of neighboring nations in a way that has imposed political systems. It has also supported and defended these neighbors against external influences such as its activities in Puerto Rico and in Mexico. Overall, it has displayed hegemony in these states through interference and dominance using a political system that ensures support and interference by equal measure.