The problem with Japan and its Socialist Government, is this is the first Socialist Government in Japan ever, all other post WWII Governments have been Right wing. The Socialists only won because the Japanese people decided someone has to fix the economy and the Right wing was NOT capable of doing so.
One of the problems when the left takes over a government is how to solve a problem the right wing had made (as is the case with Japan). It often forces hard decisions that leads to lost of popularly and the lost of the next election (Which was the case in Britain in the 1940s, 1950s, 1960 and 1970s, the Conservative party would rule, refuse to make any hard decisions, and then leave Labour win, and force Labour to take the heat. Finally in the 1970s Labour stopped, but all that set up was for Thacher to win and do even more long term damage to the economy (And to reap the riches of the North Sea Oil Fields just then coming on line, so she could adopt right wing policies AND still keep a balanced budget relying on the Oil money)
In Latin America the same thing occurred and why most the the 1960s era military government gave way to elected socialist governments, the right wing dare NOT cut the social safely net any more and hoped that the opposition socialists could do so without riots in the streets. The need for radical economic restructuring was the reason the Greek Dictatorship fell in the early 1970s, why Brazil Junta did so about the same time, and why Argentina's military Dictatorship fell after the Falkland's war (The war was started by the Argentina Junta to unite the country as the economy went into the pits). Even Pinochet had to give up being Dictator if Chile do to a deteriorating economy and an inability to get the working class to support the changes needed.
For example when the Argentina Government Collapse it was replaced by a left wing President:
http://en.wikipedia.org/wiki/Radical_Civic_UnionBasil retained a Center-Right control till 1995 then elected center-lift Presidents to fix the economy left over from the Junta (Which did NOT fully give up power till about 1990 and had strong influence in the selection of the President till the 1995 election).
In Chile, Pinochet ruled till 1990 and then set up a system of election to make it hard for the Socialist to win, even if they won the majority of votes. Thus the Socialists ended up supporting a Christian-Democrat in the 1990 election and the 1994 election. The Socialist gain control in 2000 (The third post-pinochet election) and only after defeating the Christian Democrats in a primary to be the main candidate of the Left.
In Greece, the situation was different, the left and right had strong holds over their followers but little in common. Thus the Greek Junta was the Right wing trying to force the left wing to do what the right wing wanted. The Junta only lasted Seven years and the Center-Right was able to win the next two elections, but the left never came around to the right wing thinking and the left is now in charge for the Right wing Governments did so much damage that the left finally won and now has to fix the problem caused by the right:
http://en.wikipedia.org/wiki/Greek_military_junta_of_1967%E2%80%931974Yes, part of the problem is the Greek Government imposing restrictions on the economy, not because of anything the present government did, but to repair a heavy damaged economy (damages more by Greece entrance into the EURO system then anything else).
More on the EURO:
http://en.wikipedia.org/wiki/Euro