Japan, the world's second-largest economy and a nation closely tied to the United States, is also taking a battering as the American economy pursues its destiny.

In an unfortunate coincidence, the financial crisis emanating from the United States comes when Japan has just changed prime ministers. The first acts of Prime Minister Taro Aso have included getting Japan's central bank to pour billions of yen into the market to try to steady its economy. Although the Japanese are familiar with financial firestorms, how the government responds can enhance or destroy the prospects of a leader.

Mr. Aso, 68, is a political veteran, including several years as foreign minister. He was elected leader of the governing Liberal Democratic Party on Sept. 22 by an overwhelming vote. The change in prime ministers, Japan's third in two years, followed the unexpected resignation of Prime Minister Yasuo Fukuda.

Apart from Mr. Aso's approach to financial issues, other points of vulnerability include the military support Japan provides the United States in Afghanistan through a refueling role in the Indian Ocean. It is relatively risk-free but still subject to criticism in a post-World War II Japan.

Mr. Aso also has something of a reputation, from his days as foreign minister, for annoying Japan's old enemies and current regional rivals China and South Korea by expressions of what they consider insufficient contrition for Japan's militant, sometimes rapacious, colonial past in East Asia.

As leader of Japan, Mr. Aso will need to soft-pedal the hawkishness, given that his country needs good relations with its neighbors, particularly as its longtime protector and friend, the United States, is preoccupied with its own issues.

The short-term question for Mr. Aso is whether to take the country to early general elections, as soon as next month. Elections are not required to be held until next fall, but he may decide to go for it now while he is a new and relatively untarnished leader. How Japan fares in the current financial pileup will be an important element in his and his party's decision.