One thing that the Democratic Party of Japan hoped to achieve in the wake of its historic victory in last summer's general election was to put an end to the revolving door of Japanese prime ministers. The previous three prime ministers had each served only about a year before resigning, the latter Premier after the August 30 election defeat.

The new government, backed by an overwhelming majority in the House of Representatives, should by rights be in office for a lengthy spell. That may hold true for the party, but not for embattled Prime Minister Yukio Hatoyama, who announced his immediate resignation Wednesday after little more than eight months in office. He didn't even make it to one year.

It is fair to say that Hatoyama's resignation will be quietly applauded in Washington, DC, which had pretty much written him off as a reliable partner over the continuing issue of the US Marine bases on the southern island of Okinawa. However, that will be tempered by concern over who his successor will be. Truth be said, few if any senior members of the DPJ have paid much attention to security or alliance matters in the past. Hatoyama himself confessed that the issue had been a learning experience for him,

Hatoyama fulfilled the predictions of more than one political pundit that he would have to quit if he failed to resolve the question of realigning the Marine Corps bases to the satisfaction of all parties by his self-imposed deadline of May 31 even though he never said as much himself in so many words.

Only a few days before the end of May, the prime minister basically threw up his hands and admitted he could not come up with a plan that differed in any significant way from the deal worked out with the previous government, of which the key element is to close the Futenma Marine Air Station and build a new one at another location on the same island.

The base alignment announcement pleased nobody, with the possible exception of the Americans. The news over the weekend was dominated by the decision of the small Social Democratic party to quit the coalition over it. The pacifistic party is adamantly opposed to keeping the Marine Corps air station on Okinawa at all.

The split came after Hatoyama fired SDP president Mizuho Fukushima as a minister for refusing to sign the base alignment agreement along with other members of the cabinet. The Social Democratic Party holds only seven seats in the lower house, compared with more than 300 for the DPJ. However, along with the other small coalition party it holds the balance in the upper house.

At the same time as he resigned, Hatoyama forced Ichiro Ozawa to quit as secretary general of the party, in effect the number two position in the government (or number one, if you subscribe to the popular notion that the veteran politician was quietly pulling the strings of government from behind the curtain.)

Most of the party's rank-and-file must be breathing easier to be relieved of at least one of the heavy burdens that were dragging it down. The last public approval rating put public confidence in the cabinet at about 17 percent, not much different from the rating for the opposition Liberal Democratic Party (LDP) shortly before its election debacle in August.

Ozawa in particular is a complicated mixture of old-style corrupt pol, political visionary and brilliant political technician. He is said to have been personally responsible for picking at least 100 of the successful candidates in the DPJ's election sweep last year and was counted on to perform similar magic in next month's election to the House of Councillors.

But Ozawa has been dogged by allegations of abusing election fundraising laws, allegations that never quite seem to reach the point of an actual indictment. (Hatoyama has had his own political fundraising troubles). But aside from the issue of alleged corruption, the Japanese public could never figure out who was really calling the shots in the new government.

The other cross the party had to bear was Okinawa. It is fair to say that in the euphoria of victory last summer, nobody believed that this question would come to dominate Japan's politics to the extent it did. The blame properly belongs to Hatoyama, who thoroughly botched the issue from the start, managing to anger everybody involved -- the Americans, the Okinawans and the general Japanese public.

Despite the agreement supposedly reached on May 28, the Okinawa issue is by no means settled and will be a major test for the premier's successor. Popular opposition is boiling over on the island, and, agreement or not, there is likely to be civil disobedience such as trying to block construction trucks at the Camp Schwab entrance, leading to ugly confrontations.

The government will choose a new party leader on Friday (June 4) and submit his name for ratification by the Diet the same day. This suggests that there will not be any kind of lengthy party election. “We need to make a quick decision,” said MP Hajime Ishii.

In that case, it seems very likely that the rank and file will elevate Deputy Prime Minister Naoto Kan who also serves as finance minister (although they could choose somebody else such as foreign minister Katsuya Okada, who ran against Hatoyama in the party leadership election last year).

If nothing else, Kan, 64, would break the mold of the past four prime ministers in not being the son or grandson of a previous prime minister. He is unusual for his generation of politicians in not even having a member of the Diet, or parliament, in his background. He is that rare creature of Japanese politics, a self-made man.

Like all cabinet members (save Fukushima) Kan signed the Okinawa agreement, but his opinions on security matters are not well known. Before the election he was famous mainly for exposing a cover-up of HIV- tainted blood while serving as health minister in the cabinet of PM Tomichii Murayama's coalition government in the 1990s.

Hatoyama's resignation was forced in part by the looming election next month for half of the House of Councilors, the upper house of Japan's parliament. Carrying the weight of Ozawa, scandals and Futenma, the party looked increasingly like it might actually lose seats. Eliminating Ozawa and his peculiar baggage and giving the Okinawa issue a rest for a couple months may be just enough to re set the party's election prospects.

In a recent speech, Kan was asked how long he thought a Japanese prime minister should serve. Ideally, he said, at least four years. He may have a chance to put that conviction into practice. Or not.