但在棋局的中层，十多年来经济实力一直保持着多级化的态势，美、欧、日、中是四大强国，而其他国家的重要性也日趋增加。
But on the middle chessboard, economic power has already been multi-polar for more than a decade, with the US, Europe, Japan, and China as the major players, and others gaining in importance.