Is it fair to accuse the US of destroying our national sovereignty? The issue is so little discussed that even to make the claim has parallels with the ravings of the europhobes that Brussels plans to make Britons eat square sausages. Yet consider the following seven facts, none of which depends directly on the way the US dragged Britain into Iraq, nor on the current MI6-CIA intelligence blame game about the war.

Firstly, we cannot fire cruise missiles without US permission. The British nuclear-powered submarine fleet is being converted wholesale so that it is dependent on Tomahawks, the stubby-winged wonder-weapons of the 21st century. They transform warfare because of their awesome video-guided precision. But Britain can't make, maintain or target Tomahawks. The US agreed to sell us 95 cruise missiles before the Iraq war, the first "ally" to be thus favoured. They are kept in working order by Raytheon, the US manufacturer in Arizona. Tomahawks find targets via Tercom, the American terrain-mapping radar, and GPS, its ever-more sophisticated satellite positioning system. The Pentagon, meanwhile, is trying to block Galileo, a European rival to GPS, which the French think will rescue their country from becoming a "vassal state".

Sir Rodric Braithwaite, former head of the joint intelligence committee and former ambassador to Moscow, published earlier this year a little-noticed but devastating analysis in a small highbrow magazine, Prospect, of the price we are now paying to the US in loss of sovereignty. Of the Tomahawks purchase, he wrote: "The systems which guide them and the intelligence on which their targeting depends are all American. We could sink the Belgrano on our own. But we cannot fire a cruise missile except as part of an American operation."

The second in this list of sad facts is better known. Britain cannot use its nuclear weapons without US permission. The 58 Trident submarine missiles on which it depends were also sold us by the US. Just as Raytheon technicians control the Tomahawk, so Lockheed engineers control Trident from inside a Scottish mountain at Coulport, and from the US navy's Kings Bay servicing depot in Georgia, where the missiles must return periodically. "Cooperation with the Americans has robbed the British of much of their independence," Braithwaite observed. "Our ballistic missile submarines operate by kind permission of the Americans, and would rapidly become useless if we fell out with them. Since it is no longer clear why we need a nuclear deterrent, that probably does not matter. But it makes our admirals very nervous about irritating their US counterparts."

The third awkward fact is that Britain cannot expel the US from its bases on British territory, or control what it does there. Some, such as RAF Fairford, are well known - surrounded by armed guards as the huge B52s roared off nightly to bomb Baghdad. Others are remote, particularly Diego Garcia in the Indian Ocean, where any British citizen who attempts a landing will rapidly find himself arrested. The bases are given bogus British names - such as RAF Fairford or RAF Croughton - because Britain is ashamed of all this. "The British have never questioned the purposes for which the Americans use these bases," Braithwaite wrote. "The agreements which govern them leave us little scope to do so. It is yet another derogation from British sovereignty."

The fourth fact is about intelligence. The row over scraps of British material used for public propaganda purposes - alleged uranium from Niger, alleged 45-minute Iraqi missile firing times - shows, if nothing else, that MI6 does still run independent spying operations. But it obscures the big truth: the policy-determining, war-fighting intelligence on which Britain depends is all American. The US has the spy satellites and the gigantic computers at Fort Meade in Maryland which eavesdrop on the world's communications. Britain gets access to some of these because GCHQ in Cheltenham contributes to the pool and collects intercepts which the US wants for its own purposes. This is cripplingly expensive: Britain has just invested a wildly over-budget £1.25bn in rebuilding Cheltenham. Yet it brings us no independence.

Braithwaite again: "The US could get on perfectly well without GCHQ's input. GCHQ, on the other hand, is heavily reliant on US input and would be of little value without it."

Robin Cook, the former foreign secretary, recently - and somewhat drily - let it slip to the foreign affairs committee how the US wears the trousers in the intelligence marriage. America receives all the intelligence that Britain gathers, he said. "On our side, we have full transparency." Britain, on the other hand, merely "strives to secure" transparency from its supposed partners.

These points lead inexorably to the fifth fact about our loss of sovereignty. Britain can no longer fight a war without US permission. Geoff Hoon, Britain's defence secretary, said humbly last month that "the US is likely to remain the pre-eminent political, economic and military power". Britain would concentrate, therefore, on being able to cooperate with it. "It is highly unlikely that the UK would be engaged in large-scale combat operations without the US," he said. As Rumsfeld brutally pointed out, however, the US could easily have fought the Iraq war without Britain.

The sixth fact is that Britain cannot protect its citizens from US power. Blair faces an outcry as he flies into America because the US refuses to return two British prisoners for a fair trial; rather, they have to face a Kafkaesque court martial at Guantanamo Bay.

And the seventh and final fact is that Britain is reduced to signing what the resentful Chinese used, in colonialist days, to call "unequal treaties". At the height of the Iraq fighting, David Blunkett went to Washington to be praised by John Ashcroft, the US attorney general, for what he termed Blunkett's "superb cooperation".

Blunkett agreed that the UK would extradite Britons to the US in future, without any need to produce prima facie evidence that they are guilty of anything. But the US refused to do the same with their own citizens. The Home Office press release concealed this fact - out of shame, presumably. Why did the US refuse? According to the Home Office, the fourth amendment of the US constitution says citizens of US states cannot be arrested without "probable cause". The irony appears to have been lost on David Blunkett, as he gave away yet more of Britain's sovereignty. If we really were the 51st state, as anti-Americans imply, we would probably have more protection against Washington than we do today.

· David Leigh is the Guardian's investigations editor, and Richard Norton-Taylor is security affairs editor

david.leigh@theguardian.com

r.norton-taylor@theguardian.com