Well, basically, everything is connected and interrelated. We had a colonial system until the end of the Second World War, followed by the rise of individual countries. And over the last twenty-five to thirty years what we had was the rise of China with 1.3 billion people. Because of China's rapid growth and resource dependence (iron ore, copper from Australia, Brazil and Africa, and oil principally from the Middle East), the Chinese have obviously become a very important economic force.
Take Africa twelve years ago: trade between Africa and the US was twice the size of trade between Africa and China. But today, the situation is reversed.
As a result, China has gained large geopolitical influence due to its growing economic relations. This helped shift alliances from the US to the East, which has led to tensions. China has many provinces that are larger than a European country and as an economic block, China is huge! It dwarfs everything else in Asia. But now China is surrounded by military bases in Asia, by American aircraft carriers and by the signed defense treaties between the US and Japan.