Even so, most people aren't buying it. A Kyodo News poll last week found that 63 percent of Japanese people did not support his decision to dissolve the parliament's all-important lower house, which was scheduled to expire in December 2016.

And the upcoming election will not be plain sailing for the LDP. It will take Abe into dangerous waters. Many of his policies will be challenged and are likely to sap support from the LDP. The state secret law and the Abe Cabinet's decision to expand Japan's military role overseas among others still divide public opinion.

Abe does not need an election to push forward his Abenomics or put off the sales tax hike. So what is it for? Abe has seen the popular approval ratings of his Cabinet on a downward trend in media polls in recent monthsthough they're still fairly high for an administration that has already been in office for nearly two years. But he faces an LDP presidential election in the fall next year. A campaign as early as next month will likely strengthen the ruling camp and Abe himself, and it seems reasonable to suppose that by winning a victory in a national poll he will be able to prolong his tenure as LDP president. If so, Abe might be prime minister till 2018. He would have enough time to do what he wants to do, such as writing a new Constitution for Japan.

Abe needs a win in the national election to give a fillip to his party. In an apparent backlash against Abe's security and nuclear power policies, the LDP-sponsored candidates lost the governor polls in Shiga and Okinawa prefectures. And the LDP is worrying about more defeats in Japan's quadrennial unified local elections due in April. With a low turnout expected on Dec 14 as people are weary of the febrile state of politics in Japan, Abe is looking to get a shot in the arm that will carry him through to his party's presidential election.

The author is China Daily's Tokyo bureau chief. caihong@chinadaily.com.cn