Christopher Booker's notebook
A decision announced last week means that the explosives needed for the bullets, shells and missiles used by Britain's Armed Forces, including components for our nuclear weapons, will no longer be manufactured in Britain.
Most will probably be made in France, in plants part-owned by the French state, so that our forces would no longer be able to operate without French government approval.
Such were the startling implications of the announcement by BAE Systems that it is to close its explosives manufacturing facilities in Bridgwater, Somerset, and Chorley, Lancashire, with the loss of 200 jobs.
These were among 18 Royal Ordnance plants privatised by Michael Heseltine in 1985, with 18,000 employees. Twenty years later only three remain, including that now to be closed in Bridgwater, which not only makes rocket fuel and other explosives but also the unique charges used in Britain's nuclear missiles.
Although neither BAE Systems nor the Ministry of Defence has said where the explosives will in future be made, Prospect, the professional union with many members working in these plants, was quick to warn that this would leave Britain "dangerously dependent on foreign suppliers".
Similar concerns were voiced in 2002 by the Commons defence committee, which warned that only by keeping explosives manufacturing capacity in the UK would we be able to retain an independent foreign policy.
In fact the latest move was foreshadowed in 1998 when the French Senate approved a law allowing the setting up of a new company jointly owned by Royal Ordnance and France's state-owned Société Nationale des Poudres et Explosifs (SNPE), which French MPs were told would create hundreds of new jobs.
The new law was necessary because, since the French Revolution, the state had a monopoly on explosives manufacture in France.
BAE Systems is already in partnership with another French company, GIAT, to produce guns and ammunition in France for the next generation of British armoured vehicles.
When the Army's current SA80 rifle is phased out, it seems likely that the replacement will be made in Belgium, which refused to supply Britain with shells during the 1991 Gulf war because it disapproved of Britain's involvement.
Politically, the most sensitive issue of all could be transferring outside the UK the source of the highly-specialised explosives used in our nuclear weapons.
As debate begins over a replacement for Britain's Trident missiles, the defence secretary Dr John Reid last week emphasised that, although we buy the missiles from the USA, we retain complete control over their use. Whether that would remain true if vital components had to be imported from France is much less certain.
Alerted by this column, Gerald Howarth, the Tory defence spokesman, is tabling a series of urgent questions to the MoD on the implications of this decision. "The prospect of Britain being unable to supply its Armed Forces with explosives and ammunition and being dependent on other countries," he warns, "is extremely alarming."
The one question which seemed to defeat everyone in that absurdly silly quiz set by the Home Office to test would-be citizens on their knowledge of Britain was the alternative emergency telephone number. Everyone, of course, knew 999, but no one knew 112. The story behind this was that in 1991 it was agreed in Brussels that every country in the European Community should have the same emergency number.
When this was introduced in Britain in 1994, the police received more than two million calls in 12 months. Of these 300,000 were "silent", in that the caller said nothing, but the police were still obliged to investigate. Only 500, it turned out, were genuine. The rest resulted either from dialling errors, or children playing with telephones.
A BT spokesman said: "We checked with other European countries and they all had the same problem." Despite this fiasco, which wasted thousands of man-hours, Brussels insisted the 112 service must remain in place, as was confirmed in 1998 by directive 98/10. But this has been given so little publicity that the vast majority of emergency calls are still made to 999.
The real mystery, of course, is why on earth the Home Office should regard such an arcane piece of knowledge, which might defeat most Mastermind candidates, as a test of Britishness.
Perhaps a clue to the thinking of the officials who devised the test could be found in the pictures of a typical ceremony admitting immigrants to British citizenship. They were shown standing between two flags, one the Union Jack, the other what is now known as the Union flag, carrying that much-loved "ring of stars".
Watching the Question Time television confrontation between the two Tory leadership contenders, I recalled my first meeting with David Davis at a conference in a French chateau in 1995, when he was Minister for Europe.
At dinner on the first evening, I was asked by an American economics professor, who also presented a robust Washington talk-radio show: "What do you think of Davis?" I replied, "In the right government, he would be a good man."
Two days later, Mr Davis and I marked the 40th anniversary of VE Day by wandering together round the Normandy beaches. He told me how his first act on becoming Europe minister had been to ask his Foreign Office officials to produce an analysis of the benefits and costs of Britain's membership of the EU.
When they threw up their hands in horror, he said: "If we are so convinced that belonging to the EU is a good idea, shouldn't we at least be properly briefed as to why that is the case?"
A while later I became involved in a squabble with the then transport minister, Steve Norris, over his proposal to enforce an EC directive in such a way that thousands of our most experienced lorry drivers would be put out of work, by asking them to take an eye test without glasses. Mr Norris tried to justify this in a letter to this newspaper. But shortly afterwards his proposal was mysteriously withdrawn.
When I next saw Mr Davis, he explained why. Having run the Tate & Lyle truck fleet, he said, he knew many lorry drivers and could see how absurd Mr Norris's proposal was. So, using his ministerial authority, he insisted that it should be dropped.
Although in itself this little episode would scarcely be enough to determine anyone's vote in the leadership election, I am not sure David Cameron would have been quite so quick to intervene on behalf of those lorry drivers.