No sex please, we're American
Certain aspects of the American character puzzle me. Their ardent patriotism is one. It's on display everywhere, from "God Bless America" bumper stickers to the Stars and Stripes that flutter from houses in virtually every street.
Another is their intense religiosity. No one from New Zealand - a country so irreligious that people are almost embarrassed to admit they go to church - can fail to notice the fervent faith of many Americans.
It's especially noticeable in the more conservative states, where on Sundays it's common to see acres of cars parked outside large, imposing churches, even in sparsely populated rural areas.
That brings me to another curious aspect of the American character. Public morality is an infinitely more sensitive issue there than in New Zealand.
That was obvious from the political furore that blew up over the revelation that the military hero General David Petraeus, who commanded US forces in Iraq and Afghanistan, had conducted an affair with a much younger woman who wrote his biography.
In Italy and France, it's generally assumed that prominent men will have extramarital liaisons. In fact it's almost expected of them, as if you're less of a man if you don't have a mistress tucked away somewhere.
Though the Brits tend to be more discreet, the British public too has generally been tolerant of infidelity in high places. Mild-mannered former prime minister John Major's reputation didn't seem to be seriously harmed - in fact may even have been enhanced - by the revelation that he had carried on a four-year affair with backbench MP Edwina Currie.
David Lloyd George, leader of Britain's coalition government in the latter years of World War I, was nicknamed the goat on account of his womanising (he was also, by all accounts, prodigiously endowed), and King Edward VII had a string of high-profile mistresses.
Closer to home, Australian prime minister Bob Hawke, like Petraeus, had a relationship with his biographer, the exotically named Blanche d'Alpuget, but it was never a hot political issue.
Closer still, New Zealand journalists have tended to turn a blind eye to politicians' affairs, even when they were relatively common knowledge. The general view was that it was none of the public's business unless the relationship compromised the participants politically, implicated them in illegality (as in the case of two MPs who were outed for homosexual activity before it was decriminalised) or reflected poorly on their ability to do their job.
An exception was National MP (and later Speaker of the House) Doug Kidd, whose affair with a parliamentary secretary was exposed by the feminist lobby in 1983 with the express purpose of causing him political embarrassment. The feminists were gunning for Mr Kidd (as he was then - he was later knighted) because he had moved to amend the abortion law.
Otherwise, the only recent sex scandals I can recall in New Zealand politics were those that came to public attention because they were the subject of police complaints. The politicians involved - National's Richard Worth and Labour's Darren Hughes - both resigned.
The big difference in America is that even when an adulterous relationship has been between consenting adults and there has been no suggestion of criminality, the code of public morality often demands that the public figure be punished. For a long time, a respectful American press left presidents alone. Franklin D Roosevelt had mistresses, one of whom was even assigned a code name by the Secret Service. Dwight D Eisenhower's relationship with his female British chauffeur during World War II was never referred to while he was alive. John F Kennedy scattered his seed with impunity, knowing he was protected by the prestige of his office.
All that changed post-Watergate, when the US media began applying much more critical scrutiny to politicians. Two high-flying casualties were senators Gary Hart in the 1980s and John Edwards in 2008, both contenders for the Democratic Party's presidential nomination who became soiled political goods when their extra-marital activities were made public.
President Bill Clinton was a remarkable exception to the rule. Miraculously, perhaps because of personal charisma, America seems to have forgiven him his indiscretions with Monica Lewinsky (and Gennifer Flowers, and Paula Jones, and probably others that we don't know about).
Adultery and politics are natural bedmates, if you'll pardon the metaphor. The personal characteristics that make men successful in politics - ambition, charisma, energy - are often the same as those that make them sexually adventurous and attractive to women.
No doubt that's true of many military commanders too. And it's hard not to feel sympathy for General Petraeus.
Few men wouldn't have been tempted in his situation: isolated from home and family, in a lonely, dangerous and unimaginably stressful job, suddenly finding himself the subject of flattering attention from a much younger woman. But he has paid the price demanded by a tradition of censorious public morality that probably dates all the way back to the puritanical Pilgrim Fathers.