Britain has fallen a notch in Transparency International’s 2009 Corruptions Perceptions Index. It now ranks 17th out of the 180 countries surveyed. Transparency said that the decline “reflects the damage to its international standing caused by the MPs’ expenses scandal and the weakness of its efforts to prosecute foreign bribery.”

The second item, the “foreign bribery” problem, relates to the long-running saga of allegations against BAE and arms sales to Saudi Arabia, South Africa, the Czech Republic, Romania, and Tanzania. I don’t want to downplay the seriousness of these allegations, which shed revealing light on the hypocrisy of the UK’s support for the UN’s Arms Trade Treaty, but they are old news. It’s probable that Britain’s decline was driven by the expenses scandal.

The impact of that scandal is an illustration of John Hay’s remark that “it is curious how a concise impropriety hits the public.” But it is also small beer: New Labour has brought Britain many “improprieties” that were a good deal worse but that failed to catch Transparency’s eye. There was the 2005-07 “cash for peerages” controversy, in which it was alleged that the Labour party was selling seats in the House of Lords in exchange for donations. There was — indeed, there is — the scandal of Labour’s immigration policy, which a former Labour speechwriter confessed last month deliberately sought to deceive Parliament, the public, and its own supporters.

There is the ongoing refusal of ministers to treat Parliament with any seriousness, as witnessed by the relentless leaking of government proposals in advance of the Queen’s Speech, a formerly great occasion of state. And, above all, there is the fact that more than 90 percent of all British law is now made by the EU. Compared to this, the expenses scandal is nothing: if the MPs can’t make law for their own constituents, the money they pocket on the side by fiddling second mortgages and buying expensive wallpaper is hardly the most vital national issue. Not all government corruption is financial, and the nonmonetary kinds are by far the most vicious.

But the expenses scandal is an attention grabber nonetheless. It is a very British saga — only in the UK, and a few other countries, would the public be exercised by this kind of corruption. In too many countries, it’s taken for granted that public service is an opportunity for personal enrichment. It goes to show that, though the standards have been traduced, the British public’s view of what is right in political life still stems from the Victorian era. And in my eyes, there is no higher praise than that.

It is of course true that that era was not free from corruption. If you’re a fan of old political scandals, I recommend G.R. Searle’s superb study of “Corruption in British Politics, 1895-1930,” which proves that this century was not the first time the House of Lords has been for sale. But that era nonetheless created standards that, even if they were in part aspirational, are of real value. MPs are not supposed to seek their private good. The British armed forces are not supposed to have their budget cut in the face of the enemy. Brussels is not supposed to make British law. Yet all these things happen openly and repeatedly.

Part of the sour tone of British politics today is obviously the result of the recession. But it is more than that: it is the result of the grating divergence between basic political ideals and obvious political realities in Britain. And given how influential those ideals have been around the world, and the high expectations that people abroad still have of Britain, it is not surprising that Britain has been punished by the Transparency survey.