Yasmin Alibhai-Brown: It takes an outsider to see just how rotten this state can be

I am not suggesting this country is as corrupt as Tunisia and similar regimes. But believing their country is best blinds citizens to the erosion of sacrosanct values

Week in, week out, plain-speaking natives out there notify me that I will always be an unwelcome alien, never properly British. They are right. We immigrants are destined to be insider-outsiders. The hope is that our children will belong – but their birthright too is often contested. It's all very exhausting and hurtful, yet there are advantages too. Incomers can never share the smug patriotism of the true-born.

Some of Britain's achievements are awesome, especially for those of us who fled autocratic nations run by bandits. But tyrannies make you sceptical and less gullible than those who take democracy for granted. You mistrust the powerful, question their versions of history and their motives, messages and policies.

This tumultuous week revealed starkly that gap between us and them. We clearly see the people in the ring of power, holding on to the hands on either side of them, bonded together. It is different now from when power was inherited, but the same loyalties and unspoken rules apply. The late Anthony Sampson, an exceptionally astute writer on the workings of the British state, wrote in 2004: "The British political establishment has always tended towards a single social plateau firmly based in London... The old pattern keeps reasserting itself with a different cast, still forming a narrow circle at the top."

This is the circle that tells us what to think and believe. They determine judgements, and even the language we may use. If Britons could free their minds and tongues they would see a much more disturbing picture of their beloved land than they ever allow themselves to.

The country, we are told, is fully accountable and getting more so. If that were true Tony Blair would not have been so cocky when recalled by the Chilcot inquiry. He might have been fearful that he would be obliged to reveal all his correspondence with George Bush. But nobody will make him. Why not? WHY NOT? The agony of the soldiers' families in the room was audible as the master of deceit brazened it out. They sobbed and they learnt the lesson: there is no comeuppance for the prime minister who made bogus claims and took us to war. Lord Goldsmith, the attorney general then, gave Blair legal advice, but Blair says he turned that into a "political" message. How much more proof of manipulation do we need? Blair devotees in the media still say he was a brilliant statesman, the finest there was. What I see is a Western supremacist, a warmonger (Iran next, says he!), a gun-toting US Republican groupie, a Catholic convert who has no conscience about the war dead (British or Iraqi), a consummate actor.

Here is one dictionary definition of corrupt: "immoral or dishonest, especially as shown by the exploitation of power or trust for personal gain". Blair's dubious record has led to staggering personal enrichment. His coterie has done just as fabulously. Peter Mandelson, our erstwhile business secretary, has just taken up a lucrative job as consultant for Lazard, the American investment bank that advised Kraft on its controversial takeover of Cadbury last year. Indecently soon to be cashing in, we might think. Modern political morality dictates that that's all fine. Nobody ever says that British politicians are "corrupt". Just not done.

British police too are believed to be unimpeachable. What a shock it is for the public to hear about undercover infiltrators, and (we must assume) agents provocateurs, who have gained the trust of and entry into campaign groups – most of them legitimate and exercising their right to oppose official policies. Sex romps with the enemy were the permitted perks. So when demos go violent, as the student ones did recently, I hope we will ask whether people were paid by the police forces to inject some excitement and distractions.

In Kenya, meanwhile, policemen were photographed shooting dead three unarmed suspects – a horrifying story. Rob Macaire, our man in Nairobi, condemned the officers and others who frequently use violence against the people they are meant to protect. But we too have our law-and-order thugs. Ian Tomlinson died after being struck by a police baton. Jean Charles de Menezes was shot because officers thought he was a terrorist, and there have been many more down the years. No country in the world has a spotless police force. But here, guilty officers almost always walk free or are retired, bypassing punishment for their crimes.

The same goes for other state agents. Keir Starmer, the Director of Public Prosecutions, is dropping charges against yet another secret services officer accused of complicity in the torture abroad of Muslim men. Evidence has built up to show that Britain actively cooperated with US "extraordinary rendition" carried out in some Arab states, Bangladesh, Afghanistan and elsewhere, but no one can be nailed in our secretive state. Our ministers, including the ex-foreign secretary David Miliband and ex-home secretary Jacqui Smith, have not been questioned in detail on these violations. Teflon politicians and spies slip away without a scratch.

Andy Coulson must expect the same as he leaves Downing St, even though the News of the World phone-hacking scandal happened on his watch and won't go away. He knew nothing, says the smooth spin-doctor, and there it will rest. The Met has been lackadaisical with this investigation, and we need to know why, but won't. Nor I imagine will there be too many reports on how Mr Coulson brought together Rupert Murdoch and David Cameron. Such machinations, we are told, must be confidential. Of course.

I am not suggesting this country is devoid of probity and is as corrupt and opaque as Tunisia and similar regimes. But believing their country is the best blinds citizens to the steady erosion of values and principles that should be sacrosanct. Britain is losing the moral authority to lecture other nations on good governance and justice. The powerful don't understand that a national reputation needs to be constantly renewed. Those of us who came to stay, who left behind lands of chaos and institutionalised barbarism, who have always admired this democracy, are apprehensive. Soon Great Britain will be no more, and all of us on these isles, old and new Brits, will feel the loss.

y.alibhai-brown@independent.co.uk