A contemporary thought on the changing landscape of global power is that of the prominent rise of China and the apparent decline of the US as a hegemonic power.
Authors such as Ikenberry have elegantly conceived of the possibly of such an occurrence of China overtaking the US and becoming the new global power as not happening because the structure of global politics defies history - the globalised world today doesn't play by conventional rules of interstate relations.
For one, the decisiveness of nuclear weapons in settling a war has rendered the possibility of a world war - the classical instrument for overthrowing the world order - unlikely. Secondly, the global institution based on the principles of capitalism created by the US after World War II is one that is 'hard to overturn and easy to join'. Thirdly, the many agents within the system ensure that any drastic action by any one is kept in check by a collective governance of states.
The trade regime in place creates a huge incentive for states to cooperate rather than resort to conflict. With more states within the Western order, the more wealth there is to create and gain, and the more likely one will lose out if one doesn't join in the trading playing field.
This economically-dominant system is seen as vastly different from global systems led by hegemons in the past, when the world order was created and run by the state with the greatest physical force. This contemporary and globalised world order appears benign and inclusive, more liberal than imperial, brings democracies and market societies closer together and facilitates the participation and integration of both global powers and newly developed states. This US-led world order also caters to the interests of market societies, creating incentives for states to participate and avoid being left out.
If the US focuses its efforts not in beefing the power of its country up but in ensuring that the Western order is enforced to encourage engagement, integration and restraint, countries that are rising global powers will have no choice but to play by the rules that have been established. China's economic rise is imminent, but remains checked by the system that is highly interdependent among many states. China's policy changes suggest that Chinese leaders do recognize the inevitable advantages of playing by these rules as they have increasingly embraced global trade rules.
However, history always has a sly and enduring way of ensuring that trends never change. It may be argued that the global system now may buck the trend simply because it is different. However, there is the chance that the global trade regime may fail to hold as the declining hegemonic power - The US - does what any declining power will typically do - it will desperately try to secure its own interests. One can observe this happening in its increasingly protectionist measures and socialist policies which signal its lack of commitment to the global world trading order it created and would constrain the growth of other global powers with.
By loosening its position as the foremost supporter of the global system of governance that underpins the world order, there can be (and is) increasing disincentive for countries to open up their doors to trade and resort to protectionist measures, causing liberal trade to collapse (this is especially highlighted by the neverending difficulty in ratifying trade agreements during WTO meetings). The weakening interdependence among countries can allow runaway global powers to attempt to rise up and overthrow the world order which would otherwise have been kept intact by the many countries it serves.
This seems to me to be another possible case of power shifting history occurring again, and it would signal a sense of inevitability when it comes to the tyranny of history's dictates - there can be no system so privileged that it that escapes the trend of the past.
Realists will also love to contend that the cooperation that liberalists like to proclaim as good between countries isn't so much a harmonious feature of interstate relations, but rather one that is chock-full of political conflict. As Keohane points out, harmony occurs when everyone's interests naturally align, but cooperation occurs because conflict or potential conflict arises, and cooperation then entails that patterns of behaviour must be altered.
Game theorists have shown that strategies that involve threats, punishments, promises and rewards are more effective in attaining cooperative outcomes than those that rely on persuasion, often the cornerstone of the capitalist's argument for the free market.
Cooperation hence does not imply an absence of conflict. Without the looming potential of conflict, there is no need for cooperation. The role of realism in focusing on the insecurities between states is still prevalent.
So, it is still early yet to say for sure if the new world order can hold out and that realism is dead in the idealised promise of liberal theory.