LONDON — The cars still zip over London Bridge at their typical fast clip, drawing little obvious attention.

But some pedestrians walking the bridge over the River Thames each day say they find themselves glancing at the passing traffic and wondering: Is that the one? Is that the one that's going to swerve my way? The one whose driver wants to kill me for reasons I'll never quite grasp?

"Of course I do think about it every day," said 55-year-old Phil Bradley, who notes with approval that police have installed extra barriers since the June 3 attack when three Islamic extremists slammed a van into pedestrians on the bridge then went on a stabbing rampage in nearby Borough Market, killing a total of eight people. "But you have to keep it in perspective."

Londoners tend to take their city for granted — until something goes terribly wrong. When the great city is ticking along, its residents barely notice its unique cosmopolitan blend, its seemingly effortless mix of dozens of different cultures. But when the city's multi-ethnic personality is under threat, as it is now, people are uneasy, but also proud and protective, determined not to change their routines or their outlook.

The city has endured three deadly Islamic extremist attacks in the last three months alone. And the pace of horrific events has quickened: In the last week, London's worst fire in decades claimed at least 79 lives and a group of Muslims leaving prayers marking the holy month of Ramadan were intentionally run down by a man in a van.

The city — and the country — seem divided: Between rich and poor, Muslim and non-Muslim, between those who welcome outsiders and those who fear them. Signs of division are everywhere — the general election in early June did not produce a clear majority for any party, leaving the makeup of the next government unclear.

Still, London retains much of its imperial grace: The West End theaters are full, the pubs and restaurants are jammed with people enjoying the long lingering light of balmy summer nights. But Britain has suffered a traumatic year of political change and unrest since the momentous vote one year ago to leave the European Union.

It seems the veil of civility has been lifted, and what lies beneath is not pretty. Britain, which perceives itself as a beacon of stability, seems at time to be coming unstuck, increasingly vulnerable to conflicts that have their roots abroad but are being felt at home.

The attack this week on Muslim worshippers outside Finsbury Park Mosque marks a new and long-feared escalation — an out-and-out attempt to harm Muslims simply for their faith. It comes as security officials report a dramatic increase in hate crimes directed at Muslims.

The mosque attack, in which nine people were injured, has produced a paradoxical response. Muslim residents say they are more wary and nervous than ever, and at the same time heartened by the moral support they've received from wide segments of society since the attack.

Farhad Ahmad, an imam at the Ahmadiyya Muslim Community Center near the attack site, said Muslims in the neighborhood are living with more apprehension than ever before.

"The situation in the country, there is so much more division," he said. "You see a change in the tide. The three attacks, Westminster, Manchester, London Bridge, and then this happened here as well. It seems it might be turning into a vicious cycle of revenge attacks. So we have that in the back of our minds."

He said he thinks the assailant in Monday's mosque attack believed Islam poses a danger because of the earlier violence by Islamic State-inspired extremists.

"If this person targeted Muslims thinking there is some problem with the teachings of Islam, then it means that there are people who think that on a larger scale as well," he said. "So they need to be reached out to, otherwise the divide is going to get bigger and bigger and bigger."

The deadly fire at the Grenfell Tower public-housing high-rise is not primarily about the gulf between Muslims and the rest of British society; it's about class, the widening gap between those with plenty and those scratching to get by.

At least 79 people died, with dozens more injured and several hundred displaced after the fast-moving blaze destroyed the subsidized housing tower in the wealthy borough of Kensington and Chelsea.

In the hours after the June 14 tragedy, furious residents said they had complained about dangerous fire conditions for years. But the residents — mostly poor, mostly immigrants, many of them Muslims — got the cold shoulder from the politicians in charge of London's wealthiest borough, a place where the scions of Middle Eastern potentates routinely fly in for a week of shopping in their private jets, a bright red Ferrari or orange Lamborghini in the cargo hold for their own version of rapid transit.

There is no pleasure in the "I told you so" of residents who predicted last year that only a catastrophic fire would focus attention on conditions there. Those who survived are now homeless, more dependent than ever on the government.

The fact that many of them are Muslims is a simple reflection of how people have long looked to London as a place to get a foothold and slowly build a better life. It's a pattern dating back centuries — Jews fleeing pogroms came first, settling in neighborhoods now largely populated by Muslims from the Middle East and Africa — but rarely have the divisions and resentments seemed so deep.

Those living in Grenfell Tower had hopes but little political clout. The first victim of the blaze to be identified was Mohammad Alhajali, a 23-year-old refugee from Syria. His broken-hearted family said he had come to London out of a desire to make something of himself in a city where advancement was possible, where hard work could pay off.

Other victims likely have similar tales. But their remains were incinerated, making identification weeks or months away — or impossible.

Neighbor May Naroee, who left a piece of art and a message at a condolence wall, said it was easy for the borough council to ignore the safety complaints from tower residents.

"The council wrote them off as just a bunch of Muslims," she said. "Are we not truly living in a state that is Third World if we're living in Third World conditions? These people were sent to their death in the most expensive city in the world."