The real power of a country is measured not only in terms of military strength or the size of its economy, but also by its ability to influence the world. This can include leadership in diplomacy, technology, culture, and even ideas.
The most important should be global trading. Russia, Germany, USA has the highest military strength in the world. China has the higest manufacturing and production industries in the world too. If China, Japan and other producing countries shutdown trade it will affect all the country. This is due to how almost all the country is relying on China and the rest for raw materials to carry out their own production in their individual countries. For real china global market stregnth also matters.