Edward Hallett Carr defined three major and most important types of power, and described every this type of power in his work. First, and for him most important, and most important for the classical tradition of the Realist School of International Relations, military power, the key and the most important aspect of power. States are seeking, according to Edward Carr, to maximize military power, to maximize their influence and security. And according to Edward Hallett Carr as well as the other representatives of the classic realist tradition, military power is the only instrument by which the state can protect itself, and also exercise the control over the other states. The other type of power is economic power. Economic power includes industrial, agricultural, demographic, and territorial potential of a state. And for Edward Hallett Carr, economic power serves as a basis and the tool of creating military power. Edward Hallett Carr writes in his work that economic power of the state is important because it is very important for building up of the military power. So, by this definition, we see that for him still the military power takes absolute superiority over the other aspects of the state power. Last but not least, the third type of power is a power over opinion, also known as power of propaganda. What is a propaganda? Propaganda is your ability to project your visions, to project your narrative, to project how you see the justice and rules of international relations over the other states, over your partners. Power over opinion is essentially in the bigotry of a state to influence public opinion of others. And by influencing public opinion of others, change the policy of the other states. That is why actually nowadays, many big countries invest exactly into the power over opinion, promote the media, because they believe that by doing this, they can achieve their goals and they can get control over the others' minds without applying to the military power and without using too much of economic power. Balance of power is another very important notion in international relations theory. As power remains the main regulator of interstate relations, balance of power is the key concept in allowing to understand international politics. Essentially, for the classical realist theory, balance of power is the best instrument and is the best way to achieve the peace among nations. However there is a number of concepts describing this phenomenon. First, the oldest one is the Grotian concept of the balance of powers. Enlightened self-interest makes near equilibrium, a founding principle of the society of states like Concert of Europe in 19th century, used to limit conflict, grant compensation, and overt hegemony eventually overcome war. So this balance of power house states to overcome war and this is the most important to understand. The other understanding of what is the balance of power is Machiavellian balance of power. According to this approach, balance is inevitable. States have permanent interests maintaining the scales in their favor. Balance of powers therefore is inherently unstable. And the last but not least, the Kantian tradition. Reject the power trap, both as a practice and as prescription. Balance of powers is not a conscious state policy, but the function of international system. The other important issue to understand about power is how hierarchy of power is built with international relations. A stable international order is based on hierarchy, which reflects the current distribution of power. In the most general sense, all states can be divided, can be classified, according to the level of their influence over the others, and according to their ability to influence the life of entire humanity. That's why actually super powers matter. Super powers, the mightiest states, driving the evolution of the global international system. And what is most important, capable to change dramatically the conditions of life of entire humanity. Usually, the super powers are judged by the military power, because the military, the military strength, and especially nuclear weapons, are the most important factor which unfortunately can change dramatically the conditions of life of entire humanity. So according to the traditional approach, there are two superpowers nowadays, the United States of America and Russia, because only these two countries have enough nuclear weapons to destroy our planet. Even China, the great country with a great economy, but still does not possess reportedly the equal number or the nuclear warheads with Russia or the United States of America. Though according to the economic approaches, according to the economic criteria, China is most definitely also a superpower. The second category is great powers, the states with a huge power potential affecting the international system in certain aspects. So, if we look at the map, we will see that most certainly, not only China but also countries like India, Brazil, and some others belong to the category of great powers. They are essentially matter in international relations. The third category is the biggest one, the middle powers, which are much less influential states than superpowers or great powers, which has the potential to influence politics in different regions. Countries like Germany, like France, like United Kingdom, though last two of them have nuclear weapons, will have power to change the world. Do not have power to change the international system in certain aspects, but they can dramatically and seriously influence the life in the certain regions. The next category, regional powers, which are powers which influence is very limited. It is limited by their native region. So, if France can project power and act as a military actor in Africa, for example, or Britain can do it in the Middle East or in Southeast Asia. Regional powers have influence but they cannot project their power beyond their native region. They cannot go beyond their immediate environment. Countries like Iran, Turkey, South Korea, possibly Japan, Poland, Italy, Spain, they are important in their own region. They can influence the life of their neighbors, but they cannot project power to the other regions of the globe. They cannot have influence on the other regions which are far beyond the seas. Last category is a small powers. The minor countries with a limited potential of influence even in their own native region, like most over the eastern and central European countries, many countries on the Middle East or Southeast Asia. And the last category, we call failed states, states which could not exercise power even within their own territory. Basically failing to act as a sovereign country on their own territory. But not only failed states are not doing this. We have very many minor states, very small countries like Liechtenstein, Luxembourg in Europe, which do not have military power to defend their own security by themselves. And they delegate the defense of their security, defense of their sovereignty to the other countries or military alliances. Let us look at the map of the Europe in the 19th century. Here we see the clear illustration of how the first great powers map looked that days. France, Austrian Empire, German Confederation, and late German Empire. Russian Empire have been playing the crucial role, along with The Great Britain, in building the European balance of power. Later on, the situation completely changed. Austrian empire was disrupted. France was diminished in its influence. The America appeared on the international scene. So now, we have two superpowers and a several great powers which influence their life of international community. So, according to Edward Hallett Carr, the first type of power which he actually valued most was the modern military capabilities which, can be called the power of arms which states possess in their hands, and by which they can influence their neighbors and the other members of international community. Before the twentieth century, when international relations signs emerged, the understanding of power was rather simple, but pragmatic. Professionals and rare theorist mute power in terms of military capabilities, and one state able to accumulate, to threaten, or attack another state. Such limited approach was determined by the level of social and economic development of every state. Territories carried and most important value as a source of soldiers and as sources for them. First of all, fruit. So the territory has been always defined as one of the most influential characteristic of the accumulated power of the states. So as a result, the international politics before the twentieth century was in many respects and never ending circle. States struggled for territories to get stronger, would allow them to continue farther expansion.