One of the most influential ideas in international relations is that of the balance of power. So far, no idea has been conceptualised or has been subject to so much of scholarly scrutiny in the entire field of international relations. In fact, it was in 1953 when Ernst Haas identified 8 different definitions for ‘balance of power,’ and even after about 60 years, this idea remains so debatable that even the unmodified term is too ambiguous to be meaningful.
Balance of power is a concept that refers to a situation in policy where a state or a bloc of states are defending themselves from another state, or a bloc of states by increasing their power to equal the power of the other side. The power equation can be maintained either by states or blocs, increasing their power or by participating in an arms race which involves procuring and storing a lot of arms and ammunition and annexing territories. Finally, states can also add to their power by creating alliances with other states.
In other words, states only resort to power for the sake of sovereignty and national interest as they feel threatened by the rising power of any other state. However, if the smaller states find it difficult to survive in a bloc with other bigger states, then even those states can form a relationship with other smaller states and even with the other bigger state to set the equilibrium in power. If not maintained, it can inevitably lead to war.
To understand the complexity and the importance of this theory, thinkers cite examples from the past to understand and further explain the operation of the balance of power. Another reason to cite history is that it is not just the scholars but even politicians who use this term in the field of foreign policy. The interest in the concept of balance of power is acceptable as it is considered as the basis for the functioning of the international system in the 21st century. So far, the concept of balance of power has been systemically and extensively analysed and is also considered to be a concept that arose from modern European history, and the geopolitical experience of the 20th and early 21st centuries.
History of Balance of Power
One of the essential aspects that direct the outcomes of deterrence and other contractual situations are due to the relative capabilities, which refer to the capabilities of a state in any given time. The concept of power is considered in its general aspect in the international relations literature, and realism stands out since its primary focus is related to the idea of power. It considers that all individuals and states have a desire to increase their power so that they can dominate other states and protect their own sovereignty. The realist tradition provides two opposite approaches related to the power distributions and war- Power Preponderance and Balance of Power.
The concept of balance of power believes in peaceful repercussions in power equality. Power preponderance states about the unstable condition and possibilities of war. Thus, realism provides two mutually exclusive ideas to avoid conflicts. Most of the time, one or the other state carries out military actions that can be preventative.
However, the states still do it to portray their military capabilities to the world. It is this reason in which the balance-of-power theory states that there should be no expectations regarding deterrence failure between two equal powers. While the power shift approach clearly states expectations precisely in contrast to the balance of power theory. The classical realist approach has, for decades, dominated international relations literature. It states that a balance of power helps in the creation of peaceful structural conditions. 
However, this concept was later challenged by the power transition theory that was based on both logical and empirical grounds.  Power Transition theory refers to the pattern of changing power relationships in world politics. It provides a means to measure the changes in power relations by forecasting the events that are likely to occur in the future.
A hegemonic theory refers to a theory, which states that the international system remains steady when a single country nation has hegemony in the global order. However, there is a hegemonic decline when the hegemonic state declines in power, or there is a huge power struggle by another state that can overthrow the existing hegemon.
On the other hand, global cycles or long cycles refers to the theories that try to assess the regular operations and the critical aspects of world politics in the modern era. Both these theories of hegemonic decline  and global cycles  attempted to demonstrate that many power relations run in contradiction to the classical realist model.
The arguments stated by both the schools have been but to tests on the grounds of formal models and systematic empirical analysis. After the tests, greater validity has been given to the power shift argument. Despite that, the modern study of international relations has been shaped by several adherents to the balance-of-power since the publication of classic Politics Among Nations by Hans J. Morgenthau.
Balance of Power through the Cold War
The idea of balance-of-power is ancient yet has played a crucial role in establishing modern studies of international relations. In the political essay by English philosopher David Hume, “Of the Balance of Power” (1742), he did not fail to recognise that the phrase has its origin in free-market democracies against the state-controlled markets of Eastern European states having a communist one-party system. There were several nations of western Europe as well that had aligned with the United States so that they could create the NATO military alliance. On the other hand, countries allied with the Soviet Union led to the creation of the Warsaw Pact.
The bipolar balance of power had its consequences. European countries had lost their freedom of movement due to the disparity in power between the two superpowers and other states that were present earlier helped in the creation of a flexible system. Instead, a series of unpredictable alliances were created. Several European nations had to take sides with one or the other superpower country that was pitted against each other. It led the world towards division and transformed it into two stable blocs with each bloc being led by the US and the Soviet Union. Apart from this, there have been several other decisive contrasts between the predecessor of the theory and the post-war balance of power theory.
The panic that arose due to the mutual destruction in cases such as that of nuclear holocaust loomed across policies of both the US and the USSR. It furnished both the states with an element of restraint. In cases such as a direct military confrontation between the two superpowers, which would have involved their European allies into an almost-certain nuclear war-like situation, and hence, it needed to be avoided at all costs. Thus, instead of a direct encounter, there were other ways and means with which the blocs were fighting a war amongst themselves. This period was marked by a massive global arms race and numerous political and limited military interventions by the superpowers in various Third World states nations. It is indeed essential to note that regardless of such a vast arms race, there was no use of lethal products, aka Weapons of Mass Destruction. 
In the late 20th century, when several Third World states countered the proceedings of the superpowers and China broke away from the Soviet influence, a new atmosphere ignited in global politics. This trend continued until 1990 when the Soviet Union broke down, leading to a unipolar world led by US hegemony. The world experienced the first phase of globalisation or Globalisation 1.0 post-Cold war, which lasted until recently. Globalisation 1.0 meant many trade agreements, democratic expansions, and various other developments, which were not witnessed ever before. Although this phase experienced various setbacks with events such as the Cold War, it was moving steadily on its path. Most of the nations were interdependent and were surviving alongside one another.
Balance of Power in the Post-COVID World
Unfortunately, with the COVID-19 affecting more than 218 countries, it is not hard to state that Globalisation 1.0 might end. With this virus comes the evolution of the balance of power principle considering new and emerging powers and their equations. Coronavirus has such a grappling effect that it has brought the world to a halt. Most of the countries were or are still under severe lockdown. It was during this phase that many events such as the mismanagement of COVID-19 pandemic by China, the rising influence of China in international organisations such as the World Health Organisation (WHO), the barrier in the global supply chain due to its over-dependence on China that has created a turning point at both the national and international levels.
Observers of international relations forecast a severe impact of the pandemic on the global order. Since the Cold War ended, the US has been the lone superpower. In many ways, one can argue that American hegemony has been since eclipsing every aspect of our lives for over three decades now. From choices of clothing to food to the leading industries, the US has had an impact on all people, even if they live on the other side of the planet. The US has swayed over many of all important international financial institutions that affect the global economy. The US has immense influence over the United Nations and specialised agencies.
It shows that there has been hardly anyone to challenge the US to ensure the balance of power principles. However, recently the allegations made by the US on the World Health Organization (WHO) have caused international concern for all. As well, the United States halting the funding of organisations like the World Health Organisation (WHO), marks that regardless of the political and economic control of the organisation, the flow of globalisation has surmounted the country. 
Even after being the world’s sole superpower, it could not protect itself from this pandemic. It is now that country that has the maximum number of cases. These concerns call for a discussion about whether China is substituting the US in world hegemonies or not. Arguments have been both favourable and unfavourable in China’s influence increasing or decreasing due to this crisis. The second phase of globalisation or Globalisation 2.0 would begin in the post-COVID-19 world.
This Globalisation 2.0 would be different. This phase would be particularly focussed on the post-COVID-19 era where there is a huge possibility of revamping in international organisations. Also, it would not be surprising to see new blocs being created to increase the military strength and divert the centre of supply chains. The oil prices are tumbling, and the visible effects of the pandemic are simply a small part of a larger problem. The essential part of this new globalisation that would take place in full swing is the US-China rivalry. It would again bring the world back to the bipolar balance of power principle. The same principle could be witnessed in this phase as well, and both states know that a state of war could derail the global economy. 
Globalisation and US-China Dynamics
With China being a major country as a source of the supply chain, has its pitfall. China is the heart of the global supply chain for several products like textiles, mobiles, among many others. With the world being hit by COVID-19, it had caused trade restrictions. Succeeding that was the US-China trade war that started an uprising of economic nationalism. It is these sentiments that have put a huge pressure on several nations to increase domestic production and thereby increase domestic employment. It is these circumstances that have pointed out to them over-dependence on China for the global supply, and it has put most of the countries in jeopardy.  The rising uncertainty and the consequences of the US-China trade have pushed the US and several other countries to pull out their investments from China and invests in friendlier countries in Asia. 
It is this factor that gives both reasons to have a head-to-head battle. This head-to-head battle has now moved ahead of the military might. China knows that it cannot defeat the US in terms of arms and munitions. That is why they have now moved on to not only areas that include aggressive military activities in disputed areas but a battle on another forum such as the competition to release their 5G network in the international market. China has already spearheaded this fight with its home-grown company Huawei. 
With this, we can state that with the emerging power equation, US leadership is being questioned. China, which was planning to lead a unipolar world with this situation, now knows that it is far from reality. This situation has created conditions where India is being considered as a choice of destination for the base of the huge supply chain. Also, with the rising importance of the country at the international forum, it could be possible that India would further rise.
However, any other country clashing with the US and China is far from any possibility. They both have supreme power, be it in terms of the army or their economic contribution to the world economy. One can imagine the growth speed of China since 1980. During the 1980s, China’s GDP was about $90 billion in current dollars, and today, China has an economy of more than $12 trillion. Never has a country experienced such economic growth in such a short time. 
Not only that, but the country is also having a vision of global control. For a long time China had its roots embedded in the communist ideology. The administrative structure was based on the core of the state controlling every aspect of the market and the individual. In other words, the state-controlled everything within the physical boundaries of the country. However, they realised that they would have to find a different approach if they want to place themselves as one of the major actors at the international forum. So, they instead, successfully manipulated the world by modifying their idea of communism. They moved toward capitalism while still retaining many aspects of the communist ideologies.
Since the Mao regime, China has held a huge control on the market. The state business firms had played a crucial part in the nation’s economy, with the Communist party having direct authority over state firms. Not only that, but it also tried to have jurisdiction inside private businesses. However, it only became possible since the first term in office, and Xi Jinping took over office. The Communist party has completely changed the party’s approach towards the economy, by drastically building the role undertaken by the party in both government and private businesses.
Not only that but with increasing globalisation and cost competitiveness, manufacturing jobs from the US have majorly transferred to China because of low-cost labour. It has thus allowed the state to promote and attract foreign investors by providing them with the best of the infrastructures for their industrial setup. It is through this way that they were able to attract billions of US Dollars to develop the industries in the Chinese mainland by becoming the centre for the global supply chain.
Owing to all these aspects, the world economy went under due to the COVID-19 in China and their subsequent mismanagement for the virus. This eventually made the world realise that the supply chain was in China, and everyone was dependent on the country for manufacturing purposes. With major economic activities being hit across the world, it is having a huge impact on how the countries are now dealing with the situation. Revenues being lost and the whole world suffering from this pandemic, and the way with which China has dealt with the crisis has made most of the countries to stand against it.
So, a global shift in geopolitics is surely expected after the pandemic is over. There would be a rise of a new hegemon. With countries isolating China, it would be gruelling for the state to fill the vacuum created by the lack of American leadership. China requires mastering a lesson- one cannot sway over other countries by rolling over them. A world order with China as an ascending player. Also, there is a possibility of the rise of India in this situation. Even so, one cannot change the fact that the post-COVID-19 world order and the consequent influence in the international organisation are inevitable.
In sum, the balance of power has been used both practically and theoretically throughout history. Now, the question is whether there has been any situation in the world to create a successfully balanced power with the US on one side? Is the world unbalanced? Well, this question is debatable in its manner. However, few incidents do put the US hegemony into question. The 9/11 terrorist attacks do raise doubts about the power of the lone superpower, and it is at this point that it comes to light that the balance of power does not consist of only the governments but consists of other players as well. It now includes non-governmental organisations, international governmental organisations, multinational companies, and even terrorist organisations.
First, in the context of increasing Russian assertiveness in the 2010s, and then that of China, one can find references by the media on the balance of power principle. It must be prevalent across all nations; however, there is no clear-cut definition of this principle in the international relations realm.
Some several actors and scholars are relying on various thoughts for different purposes, and sometimes even those thoughts that are having contradictory meanings. Hence, these thoughts can be of analytical value if used with care for the study of diplomacy, but the balance of power principle is also certainly worth reviewing as being a crucial part of the historical practice of diplomacy up until the present day. There has been an evolution of the balance of power principle considering the emerging power equation. Moreover, the final answer to this question will only be unravelled with time.
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