The Queen's guards sit impassively in their saddles.
Choirs sing in St Paul's Cathedral. Tills beep in Oxford St and Regent St. People queue outside the Les Miserables theatre in Charing Cross Rd.
Britain might be at war, but there is no feeling that war has arrived in Britain. Like the Gulf War, the strikes on Afghanistan seem to exist only on television.
Although many Londoners admit to be worried about retaliation, they are following the official line of "business as usual".
Prime Minister Tony Blair has urged people to act normally - "To work, to live, to travel and to shop, to do the things they did before September 11."
More than 1000 extra police, many armed, are on duty around the Ring of Steel city centre and at airports, other Government buildings, the Canary Wharf business hub and mosques.
It is called Operation Calm. But even as Blair calls for calm, he is careful to emphasise the risks enough to justify Britain's stance alongside the United States in the raids on Afghanistan.
He acknowledges that London is a target for retaliation, but says there is a bigger danger if the attacks go unavenged.
"We know that if not stopped, the terrorists will do it again, this time possibly in Britain."
Londoners speculate about planes crashing into Canary Wharf or the central city and gas attacks on the Tube, but they still catch the Underground to work every day.
It's common to hear the "I've got more chance of getting run over by a bus" analogy.
An urban myth that Britain is about to be attacked has been doing the rounds this week, followed closely by police assurances that it is false.
The story goes like this: a friend of my mother/brother/cousin/flatmate was in the post office/Harrods/petrol queue when a man in front of them, an Arab, dropped his wallet/found he was £1 short. The friend handed him the wallet/gave him £1. On leaving the shop, the Arab was waiting for them.
"Because of your kindness," he tells them, "I want to warn you: do not travel on the Underground/travel to Central London/visit Wolverhampton/travel by train to Liverpool on Saturday/Tuesday/Wednesday."
But people are more concerned about the risks of leaving Britain than staying.
The travel industry is facing a huge slump as Britons cancel overseas travel. Travel agencies and the major airlines are announcing redundancies, although the budget airline business is conversely booming. Tourist operators in London are feeling the pinch as Americans, too, stay home.
The economic indicators are confusing and it is hard to gauge their link to the war. Despite talk of economic downturn, retailers say September was a bumper month, perhaps because cancelled overseas trips left more money in pockets.
Other industries are talking about a downturn. Prominent media businesses have announced redundancies and no-hire policies as advertising slows. Situations vacant sections of newspapers are getting slimmer.
The demand for secretarial temping work has dried up as office workers cancel holidays, affecting hundreds of young Australians, New Zealanders and South Africans who prop up the market in London.
West End shows, which rely heavily on American tourists, are struggling.
But if there is a British frontline for this war, it is at the airports, where even nailfiles are being confiscated as potential weapons.
There are lapses. An Auckland man who flew to Spain from London's Luton Airport this month said he saw a woman getting held up by security guards for having a pair of tweezers in her handbag. "Then, after security checks, I had the option of buying duty-free a massive Swiss Army knife/foldaway machete which I could happily have carried on board."
This is said to be London's biggest security threat since the Blitz, and there have been blunders.
Home Secretary David Blunkett was quick to suggest mandatory ID cards be introduced to Britain. He later tempered the announcement by renaming them entitlement cards, and then eventually withdrew the suggestion altogether, when it was pointed out they would cost about £1 billion ($3.5 billion).
Blunkett still made it into Blair's newly formed war cabinet, which is now the focus of Britain's war effort.
Meanwhile, chaos is forecast for London today and tomorrow - not because of the war, but because of the threat of Tube strikes.
