First, an apology, to David Miliband and his wife, Louise: the last thing they will want to see today is a column in The Times about adoption. But behind the private arrival this week of their second adopted son, Jacob, there is an important public issue.

A fair amount has been written in the past two days, under cover of faux concern about a diplomatic faux pas, about the Foreign Secretary's failure to show up for a meeting with his Saudi counterpart when Jacob arrived two weeks early. Don't believe for a second that this is about diplomacy: can you imagine anyone raising even an eyebrow let alone a banner headline were a politician to cancel a meeting because his wife was giving birth? The story simply provides cover to report a second adoption by the Milibands of a baby born in America. The family was rightly upset by suggestions, when they adopted their first child, Isaac, three years ago, that they had somehow abused Mr Miliband's position as a Cabinet minister to fast-track the adoption.

It was utter rot: his wife has dual nationality and so the Milibands are entitled to adopt in the US. Every person I know who wants to adopt a child would jump at the chance of adopting there if they were only entitled to. It isn't true either that authorities in the States allow parents to “buy” a baby; what they ask is that you pay the mother's medical expenses, which can run into tens of thousands of dollars.

The moralisers should stop criticising the couple and ask a different question instead: why is it that a British foreign secretary and his wife, a professional violinist, are unable to adopt a young baby in the UK? Why, when there are thousands of babies under the age of 1 in the British care system, did they have to go to America at all?

The British adoption system, despite repeated promises from politicians to improve it, gets it all wrong. Far from ensuring that babies are handed as quickly as possible to a family that wants and can look after them, the State contrives to lock newborns into the care system. In the US, where private and voluntary agencies match parents with children, a mother may choose the couple who will adopt her child before the birth. She can get to know them, they can attend the birth and form the earliest possible bond with the baby.

In Britain, where the system is run by local councils, the presumption is that a baby should stay with its mother wherever possible, or be removed short term and returned to her. This is arguably more in the interests of the mother than the child. Even when adoption is agreed on as the only, last-ditch option, the baby is put into the care system. The lengthy process that follows means that most children are more than a year old before going home to their adoptive family. That family will itself have been through a crazily detailed and intrusive vetting process that can last years, and which excludes perfectly decent parents on the grounds of age or other random factors.

A survey by the British Association for Adoption and Fostering (BAAF) two years ago found that 12 per cent of infants under the age of 2 in public care in England had been moved three or more times in the previous year. Yet experts say the trauma of moving to live with a stranger causes damage to a baby's brain that can be irreversible. BAAF found unnecessary delays, inexperienced social workers and slow legal processes in a system unable to respond swiftly to a baby's needs.

It doesn't take an expert to recognise that a young baby needs a stable family as quickly as possible after birth, and preferably from birth, to form a permanent bond with at least one adult. The British system makes this impossible. At the end of March 2006, the most recent period I can find figures for, there were 2,900 babies under a year old in the care of local authorities; only 190 children under 1 were adopted that year.

The State is a terrible parent, yet in England we entrust it with the care of our most vulnerable children. Read the devastating report into the care system written last year for the Centre for Policy Studies think-tank (Harriet Sergeant, Handle with Care), which found that three quarters of teenagers leaving care had no educational qualifications, half would be unemployed within two years and more than a sixth of them homeless. Just 1 per cent would go to university. Half the country's prostitutes and half of all prisoners under the age of 25 have been in care.

There are about 60,000 children in care at any one time, more than a third of them under 10. The vast majority are taken in because of abuse, neglect or dysfunctional families; it isn't their fault. Nobody reads them bedtime stories and they are ten times more likely to be excluded from school than other pupils. One teenage girl in care described her dream: “Mum would be in the kitchen cooking dinner with the washing machine going. I would get a drink from the fridge and go into the front room to watch TV.” As Ms Sergeant wrote, the very banality of the dream is a rebuke.

The State is too unwieldy a parent. Children, particularly abused and frightened ones, cannot be funnelled through a rigid system. Knowing as we do how bad the State is at looking after the kids entrusted to it, we ought to be encouraging the earliest possible adoption through the swiftest, simplest route. Yet government policy turned recently from encouraging more adoptions to improving the lot of children in care.

While a children-in-care Bill forms a central part of the Queen's speech next week, new money ring-fenced under Tony Blair for local authorities to increase adoptions stopped last year, since when there has been a 12 per cent drop in adoptions. The number of looked-after children adopted under the age of 1 has also fallen steeply. This side of the Atlantic, the State wins.

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