When the Democratic Party of Japan (DPJ) swept to power in 2009, ending 54 years of virtual one-party rule, one of its most controversial policy platforms was to establish a friendship with China that balanced the close post-war relationship with America one of the hallmarks of the Liberal Democratic Party's rule.

ECONOMIST: Friends and neighbours

Both parties have been pushed towards their respective extremes, but one party must rule and so the effects on the Republicans, as the minority party, have been worse.

ECONOMIST: California��s Republicans

America has only had one-party rule (with the same party controlling the White House and both chambers) for six years out of the 28 since Ronald Reagan's election in 1980 two years under Bill Clinton and four and a bit under George Bush.

ECONOMIST: Lexington