One of the most troubled economies in the world is:

The choice of Japan as one of the most troubled economies in the world is rooted in several significant economic challenges the country has faced over the years. Japan has been grappling with a prolonged period of stagnation often referred to as the "Lost Decades," which began in the 1990s after the asset price bubble burst. This period has been characterized by low economic growth, deflationary pressures, and an aging population leading to a shrinking workforce.

The economic landscape in Japan is complicated by its high levels of public debt, which is among the highest in the developed world, leading to concerns about fiscal sustainability. Additionally, Japan has struggled with productivity growth, and innovations have not translated into widespread economic benefits across the economy.

In contrast, the other countries mentioned have not faced the same magnitude or combination of economic challenges. For instance, Germany, known for its robust industrial base, has experienced solid economic growth, despite facing challenges related to its energy transition and labor shortages. Australia has maintained relatively strong economic performance supported by natural resources and a diverse economy. Greenland, while unique in its economic context, does not face the same extensive challenges as Japan.

Thus, Japan's specific historical context, ongoing economic conditions, and demographic issues make it a standout example