In world politics it is evident that some countries are more powerful than others and that, in various ways, the powerful dominate the weak. However, this is not as simplistically true as it at first seems. In my lifetime I have seen Vietnam, one of the weakest nations, defeat the USA. Dominance is not automatic and much depends upon the strength of motivation of opponents. The British empire was substantially made possible by the ability of the colonial power to recruit sections of the local population in countries that were colonised. Every ruler needs at least some friends.
It can be advanced as a reasonable hypothesis that an empire will persist for a length of time that is inversely proportional to the selfishness of the imperial power. When the dominant country is solely concerned about its own interests and sees the dominated countries simply as resources to be plundered, then the motivation of those who oppose it will become strong. When, on the other hand, the imperial power has some ethos of service toward its vassals, at least some of the population of those vassal countries will see it as a privilege to be associated with the dominant country. Some hegemonies last longer than others.
In the postwar period I think we have seen a gradual change - with some exceptions - in the attitude expressed by the leaders of the currently most dominant country. There was a time when America regarded itself as having a responsibility toward the rest of the world. More recently, the strongest note has been that America must look after itself and only be concerned with its own best interest.
The basic drama of world politics in the current century is bound to revolve around the question of whether America can manage to retain its position as the most powerful country on the planet. It seems to me that there is no single country that has the capacity alone to challenge that position, but that American dominance could come to an end if it found itself faced with a consortium of opposition from other countries acting in concert.
Insofar as America becomes more and more blatantly self-seeking, the likelihood of other countries overtly or tacitly uniting against it must become greater. The new regime now taking office is unprecedentedly strident in its America-first attitude. This has already been enough to bring cries of alarm even from some long standing allies and one can imagine that, behind closed doors, leading politicians in many countries are now making contingency plans.
It is a Buddhist principle and even more so a Taoist one that the person who just thinks of himself is least likely to get what he wants in the long run, and sometimes even in the short one. America will be judged by its actions more than its words, but words are not nothing. It is possible that the days of American dominance are numbered. It is impossible to tell exactly how the downfall will work out. Much depends upon adventitious circumstances that cannot be foreseen. However, on the basis of first principles, it is not unreasonable to imagine that some large scale changes are not that far away.
When we think in a purely utilitarian manner, we are liable to be blind to the factors that really move people's hearts and minds. The single action that probably most tellingly accounted for America losing in Vietnam was the decision of Lindon Johnson to bomb Hanoi. One might think - probably LBJ did think - that increasing pressure on the enemy will advance one's cause. However, what it did do was to harden the resolve of the Vietnamese to get rid of the foreign power. Penalising European industries that want to do business with Mexico might go down well with certain sections of American home opinion, but, as a German industrialist commented, Europe also has ways of putting pressure on America. When your former friends start to talk like your enemies, it is time to worry. We are not yet in a trade war, but it might be on the way and if it happens it is certainly not obvious that America would win it.