The trouble with socialism, Margaret Thatcher said, is that eventually you run out of other people's money. Brits are now learning that the hard way. Britain's welfare state reached an absurd peak in 2008 when it began offering benefits for the extra wives of polygamous immigrants. But that era is now over, say the Conservatives, who announced massive cuts to fight a deficit of some $235 billion this year. "Today's the day when Britain steps back from the brink, when we confront the bills from a decade of debt," Chancellor of the Exchequer George Osborne said last week. It's tough...