In 1949 the British government established a Permanent Under-Secretaries' Committee "to consider long-term questions of foreign policy".
"After a searching review it had concluded that the interests of the United Kingdom . . . demand that her present policy of close Anglo-American co-operation should continue. The cultivation of the American relationship was thereby acknowledged as being the cornerstone of Britain's foreign policy." (Quoted in Britain and the Congo Crisis 1960-63 by Prof Alan James (1996)).
This became one of those vital decisions, often quietly taken, on which governments base subsequent actions and policies. They tend to be adhered to through thick and thin, sometimes with dysfunctional results. Abandoning them can be worse, as Britain found at Suez in 1956.
There was some sourness in the British Establishment, but the Under-Secretaries who produced the report were above propaganda and illusions. They knew Britain's parlous economic state and the hard decisions needed about the empire.
The policy largely explains Britain's almost unfailing support for the US (though she refused troops for Vietnam). It has clearly been the right policy for Britain, despite occasional rough spots. Disagreement on the war's next phase seems temporarily shelved. Some US government members want to attack Iraq, and perhaps Iran, Libya and Syria.
Troops and arms are ready. Col Summers, in his highly acclaimed book on the Vietnam War, says that America tried to fight "in cold blood", without what Clausewitz called "the strength of the passions of a people mobilised for war". It may be an unattractive concept, but this strength seems required for prosecuting mass wars.
Desmond McCarthy described the crowds outside Buckingham Palace in 1914 "roaring for their own death" in words remarkably like those of Reck on the Berlin crowds before the Kaiser's windows, who "roared in tempo".
Neville Shute wrote of similar scenes in Moscow. Bin Laden has now mobilised that strength in America, without crowds roaring for war.
Claims about the anthrax attacks change continually. On October 26th, a well-reasoned article by the Daily Telegraph technology correspondent showed that the anthrax used in America probably came from an American, British or South African stockpile.
Then Bild, the German magazine, quoted Israeli sources saying it came from Iraq. The old test of cui bono seems advisable.
The September 11th attacks, like Pearl Harbour, have probably reinforced America's belief in a fundamental doctrine. The US military has held that in assessing an enemy's possible actions one should look at his capabilities, not just his intentions or likely actions.
Capabilities are relatively straightforward to assess if one has enough intelligence about enemy equipment, manpower, morale, etc. Intentions are more difficult.
It used to be argued that only America, with its huge strength and resources, could provide against all the possibilities that a consideration of capabilities would pose.
Better eliminate the way-out ones and concentrate on what is likely.
It may be pointed out that the Pearl Harbour attack succeeded, as did the initial Ardennes breakthrough in December 1944, when Germany seemed on her knees.
But these aberrations proved the doctrine. If all capabilities had been considered, precautions might have been ready. But who would have envisaged the September 11th attacks in assessing bin Laden's capabilities?
Perhaps, looking at America's power, opponents have to think the unthinkable.
But the effectiveness of September 11th will probably drive the US military into further efforts to assess and guard against all enemy capabilities - at every level.
Allies will find it hard to keep up with this, although underestimating a potential enemy's capabilities can nullify years of expenditure, as 1940 showed.