One of the most complicated things is to explain to new students what are the complex dynamics through which our international system is evolving. In my new semester I have just started teaching, a half of my students are foreign, a lot of them are from Asia, especially from India and China. 

As I launched into international politics, the concept of Thucydides Trap started to come up often, an idea that a growing power and a static power are essentially destined for conflict, and is at a conflict more often than not in history. 

However, that view is now considered simplistic in some circles. First of all, nuclear power has made great power warfare obsolete. Second, how can there be a conflict when the trade is so closely interlinked? After all, isn't that why Indians and Chinese students filling up Western universities?

This idea that the future of global politics is progressive and cooperative is undergoing enormous strain right now. Is the Thucydides Trap certain and manifest destiny, or is it, as one of my Chinese students put it, a nonsense? Is there going to be a new cold war, a hot war, proxy wars? Is history a good way to measure present and future, given that the time of Rome and Carthage was very different to Britain and Germany, U.S. and USSR, and now the U.S. and China? 

The answer is yes, and no. First of all, the idea of Thucydides trap is perhaps the most misunderstood. The concept doesn't mean that there would, inevitably, be a war, or even a conflict. It doesn't predict anything, it doesn't even claim to have any predictive power. It is an explanatory theory, which talks about systemic power transition in the world, and the behavior of great powers, instead of predicting actual foreign policy. 

China and the United States are tied together in ways that no other great power has ever been. However, so was Britain and Germany, the two largest trading partners, before the First World War. Britain and Germany didn't have nuclear weapons, and there was never any chance, of global catastrophe, or the extinction of life on this planet, as there was between Soviet Union and United States after WWII, just like there's now one between Beijing and Washington. 

As John Mearsheimer has written, nuclear weapons made great power conflict obsolete (almost). That being said, there's no guarantee of peace, because hoping for peace is futile in global politics. 

Consider the evidence. When the U.S. changed course on Iran, eventually everyone fell in line. The European Union, which is determined to save the Iran deal in the long term, fell in with short-term considerations and agreed to follow the U.S., as did Iran's biggest crude oil partner, India. 

The reason is simple: the U.S. controls the economic system and the default currency and banking system. 

The second and even bigger example is the ongoing trade war with China. There's no question that this is extremely unpopular with Americans, and the retaliatory protectionist measures are pushing prices up on items of daily use like beer cans, which are hurting the middle and lower-class people far more than others. 

Finally, in what could be a new bloc formation, the USMCA, or the renewed NAFTA agreement, has a termination clause, which nullifies any trade deal with any country that is deemed a “non-market economy.” So, effectively, Canada and Mexico, which are part of the deal, would not be able to strike a deal with any non-market economy country, as that would be nullified by the U.S. 

This wouldn't have happened if all three were equal powers. However, as Canada realized, American heft and power is what matters more, and Mexico then went and cut a deal behind Canada's back. Power, and expediency, therefore, is more important, than values, norms, or even ideological solidarity. 

History is complicated, and situations are different, but some things remain the same. If you don't have force to back up your convictions, or your ideas, then these don't count for too much. Principles are fine, both in real life, and global politics, but without real power, those principles will not even have a chance to reach people and survive the global ideas marketplace. 

This is what my students, are starting to learn, as they try and navigate the darkening political scenario of their times. One should rather be prudent and prepared, than optimistic.