国际英语新闻：Commentary: Three PM elections in a year upset Japanese politics

BEIJING, Sept. 14 (Xinhua) -- Three elections for prime minister in a year reflect the embarrassment and volatility of Japan's political system.

Japanese Prime Minister Naoto Kan won the leadership vote of the ruling Democratic Party of Japan (DPJ) on Tuesday to remain the country's leader.

Whoever wins the party election will become the prime minister, because the DPJ has a majority in the lower house of parliament.

Kan collected 721 points out of the total 1,222 points up for grabs, while DPJ kingpin Ichiro Ozawa obtained only 491 points. The votes were cast by DPJ's 411 members of parliament, local DPJ lawmakers, and party members and supporters.

In the 1990s, Japan's economy slowed and stumbled forward during the so-called "lost decade." Since 2000, except for former Prime Minister Junichiro Koizumi's five-year continuous governance, the average of all other prime ministers' terms is less than a year.

The DPJ secured a historic victory in the general election in August 2009, breaking the Liberal Democratic Party's almost unbroken rule for over half a century.

Yukio Hatoyama was the first to serve as prime minister after the DPJ's election win but he stepped down in June after failing to follow through on a promise to move an unpopular U.S. military base from the island of Okinawa and amid a political funding scandal.

Kan succeeded Hatoyama after winning the ensuing DPJ leadership election.

But only three months later, Kan Tuesday had to endure the acid test of another party election, after the DPJ lost seats in upper house elections in July, a result blamed in part on Kan's stance on raising consumption tax in a bid to reduce Japan's massive public debt.

The frequent change of Japanese prime minister is attributed to the country's economic performance, political system, party mechanism and public opinion.