Why, it may be asked, is Tony Blair coming to Pakistan today instead of Donald Rumsfeld? Could it be anything to do with the large number of effigies of George Bush that have gone up in smoke here during the past three weeks?
Washington has been showing signs of deep unease with its long-term south Asian ally ever since Pervez Musharraf seized power in a coup almost two years ago. President Bill Clinton did actually visit Pakistan, the only important world leader to pay the general that honour until Mr Blair's visit today, but it was one of the more extraordinary diplomatic events of recent times: dubiously and controversially tacked on to the fag end of Clinton's tumultuously successful Indian tour, it lasted half a day.
A succession of decoy Air Force Ones landed at Islamabad's airport to reduce the probability of the President being blown up; several armour-plated black limousines rolled through the capital for the same reason. Mr Clinton refused to smile and did not even permit a photograph of the two of them shaking hands.
That's a measure of how much the world has changed. Pakistan's self-declared President is now the West's valued ally; Pakistan, tossed in the strategic garbage bin in preference for huge, sexy India, finds itself fished out again. And mirabile dictu, here comes Mr Blair to press the flesh.
It's unlikely, when they were deciding who should go where this week, that Mr Blair plumped for Pakistan on the grounds of Raj nostalgia, Commonwealth fellow-feeling or affection for the Queen.
Pakistanis still smoke Gold Flake cigarettes and drink Lipton's tea, and the defence of Pakistan's realm takes place in the vast and still gleaming cantonments the British built to defend what was always the most troublesome and volatile part of the Indian empire. But for the Islamist hardliners here, Mr Blair is just another crusader, representative of the two nations explicitly targeted by Osama bin Laden, military and civilians alike, for righteous attacks.
And what can he hope to achieve? What can he realistically ask the general to provide? Despite the trappings of absolute power, Pervez Musharraf this week finds himself in the most ticklish quandary any Pakistani leader has ever confronted. And it is ticklish in the same skin-crawling, incalculable way that life in the West is now terrifying and strange. The dangers are hiding in the shadows, biding their time, keeping their ammunition dry. No one knows how or where or when they will strike, or how far General Musharraf dares to push his pro-West line before they strike for all they are worth.
It is likely, for example, that General Musharraf got a vivid glimpse of the fanatical power on the side of his hidden enemies on Monday, when an attack by a suicide bomber on the state legislature of Srinagar, the summer capital of Indian Kashmir, killed 34 people and injured more than 70.
Ostensibly an attack on Indian rule in Kashmir, it was in fact directed squarely at General Musharraf. Responding to the West's demands in the wake of 11 September, he has moved to shut down some of the mujahedin outfits fighting India in Kashmir which have their offices and training camps in Pakistani Kashmir.
Pakistan has always maintained that it gives Kashmir's "freedom fighters" - who include associates of Mr bin Laden - moral support only; the world has always, with good reason, believed the support went much further. The struggle to "liberate" the Muslim-majority state of Kashmir, generations of Pakistanis have been told by their rulers, is at the heart of Pakistan's identity. Now President Musharraf must execute a U-turn and tell his people that no, that was all rubbish, actually these are terrorists just like the scoundrels who killed all those innocent people in New York and Washington.
That's what the West wants him to do. But if the general's utterances have been getting more mouse-like these days, it is because that is one thing he cannot bring himself to say - for at least three reasons. One, he himself was, as Indians like to say, the "architect of Kargil", the mountain war of 1999 that was Pakistan's last, doomed attempt to prise Kashmir away from India. Two, he cannot do it because when he makes a gesture in that direction mass murder occurs in Srinagar - distant thunder warning of terrible storms at home if he pushes his luck. And three, in his new guise as the West's obedient servant, he cannot betray the "freedom fighters" of Kashmir because their comrades are deeply insinuated in high positions in every important institution of the Pakistani state.
The people who brought the Taliban into existence, who funded and armed them, who gave this rag-tag band some know-how and pushed them in the right direction - they have been sitting across the officers' mess from General Musharraf throughout his career.
So if Mr Blair's conversation with the general is punctuated by long, pregnant pauses, there is a reason. He has made the right noises; he has offered use of airspace. What else can he offer? And what price would he pay? The most obvious and in a sense important contribution he could make is intelligence: no one knows more about what is happening inside Afghanistan than Pakistan's Inter-Services Intelligence Directorate (ISI). But the reason it knows so much is because the ISI is staffed, at least in part, by true Islamist believers. So it is impossible to know the value of the intelligence offered.
"You never know who you are dealing with," a US official told The Washington Post anonymously this week. "You're always dealing with shadows."
According to reports published in America this week, on seizing power on 12 October 1999, one of the first things General Musharraf did was to abort the joint operation between the US and the former prime minister, Nawaz Sharif, to capture or kill Mr bin Laden.
But he will shake Mr Blair warmly by the hand today, and he will proceed to do as much as he dares to betray the freedom fighters/terrorists of Kashmir and his own past - because to do otherwise would be to deprive Pakistan of all influence over what form the next government in Kabul takes.
It would be to invite the Russian bear, in the guise of an American-backed Northern Alliance, to squat on his Western border, hungrily eyeing the warm waters of the Arabian Sea. And that, as all his predecessors, British as well as Pakistani, could tell him, is one thing you must never do.