When Sir James Crosby, the formidable chief executive of Halifax who merged it with the Bank of Scotland to create HBOS, retired at the age of 50 this summer, some of us wondered why - and how he intended to spend his time.

As the example of the luckless Lord Browne at BP has demonstrated since, the most glittering reputations are the most vulnerable.

It can be wise to step aside at the pinnacle of success rather than cling on while things unravel.

Not that Sir James hinted at anything of the sort.

He just insisted that he had no job lined up. Yesterday Gordon Brown let drop what Britain's highest-rated exbanker is doing.

Mr Crosby is heading a "public-private" forum to come up with ideas about how to "join up systems for verifying identities and protect against theft and reduce inconvenience".

He is to report to Mr Brown in time for next year's Budget.

Identity theft is a plague of our time.

So is lack of joined-up Government.

It is plainly a good idea to have a banker who knows the relevant technicalities and how they fail - and is also out of the loop of political and departmental rivalries - to come up with ideas about combating this fraud without making life intolerable for honest people using the

services of the bank of their choice. Yet, considering the offers of chairmanships or what have you Sir James doubtless turned down, surely he is punching below his weight toiling away on a private report for Mr Brown?

Or perhaps not.

Yesterday the Chancellor slipped in the news of Sir James's task in a resounding speech, part nitty-gritty, part wide-ranging philosophical, about security and terrorism. It had the ring and range of the job application that Mr Brown failed to deliver at the Labour conference - so that it is still he, in all probability, who will deliver the Budget next spring.

In that context, Sir James has a top-weight job on his hands. Mr Brown pointed out, what he and earlier Chancellors have often over-looked, that the main job of any

Government is to protect its citizens. Nowadays that entails depriving terrorists of access to money to fund their activities and following the trail of that money to track them down.

That is why the Bank of England puts out notices banning dealings with this bank account or that every week or two - there was a new one yesterday. It is also why your bank sends you upstairs to join a queue in the "business centre" if you want to cash a cheque for £1,000 or more, and why you cannot open a savings account for your grandchild without a birth certificate and a parent's utility bill.

Mr Brown decreed all this anti-money-laundering stuff after September 11, 2001.

Maybe it has spared us some horrors.

You rarely hear of plots that fail to hatch - though that foiled in August does look like coming to court.

Yet it all seems a bit niggling when fraudsters can siphon off billions from the VAT system for years on end.

It would be comforting to know that none of them are terrorists.