Tunisia's special forces secure the beachside of the Imperial Marhaba resort, while British, French, German and Tunisia's interior minister arrive to pay their tribute in front of a makeshift memorial in Sousse, Tunisia, June 29, 2015 (Photo: Reuters)
Britain will pay silent homage on Tuesday to the 52 victims of the 2005 London bombings, with thoughts inevitably also turning to the 30 Britons killed in Tunisia last month in a horrific reminder of the Islamist threat.
In the 10 years between the two attacks, Britain has beefed up anti-terror legislation and stepped up its emergency preparedness, but the number of fighters travelling to join jihadists has multiplied.
The four suicide bombers of July 7, 2005, who killed 52 people, said they were inspired by Al-Qaeda, while the Tunisian gun massacre of June 26 in which 38 tourists died was claimed by the Islamic State group.
A wreath will be laid in front of a memorial in London's Hyde Park to the victims of the attacks on the city's transport system ahead of a religious service in St Paul's Cathedral to mark the tenth anniversary, with families of the victims and survivors expected to take part.
The country will observe a minute's silence at 1030 GMT after having made the same gesture on Friday in honour of its latest victims of terror.
The July 7 ringleader Mohammed Sidique Khan, a father-of-one whose parents were immigrants from Pakistan, was angry at British foreign policy in Iraq and said he wanted to avenge the deaths of fellow Muslims.
Khan's suicide video was widely broadcast and left a scar in the national consciousness, with many Britons shocked at hearing the jihadist slogans from the mouth of a young man with a recognisable hometown accent from his native Yorkshire.
John Tulloch, a British-Australian man who was on the train targeted by Khan, remembers the moments after the blast: "The darkness, smoke, glass everywhere."
There were "horrifically wounded people right next to me, the dead young man spreadeagled at my feet," he told AFP.
The physical pain endures from the shrapnel lodged in his head but more painful still are the images that still form "a frightening tapestry of memory".
To overcome the trauma, Tulloch started writing about the attacks and the war on terror, and he learned to live with the idea of having narrowly escaped death.
Once the initial shock of the attacks passed, London prepared to minimise the risks of a repeat attack.
July 7 "changed the whole landscape for UK counter-terrorism strategy," said Hugo Rosemont at the Centre for Defence Studies at King's College London.
The emphasis has been on countering radicalisation but also improving the effectiveness of the emergency services, which were criticised for delays in 2005.
"We've learned a lot as London's emergency services," said Jason Killens, director of operations at the London Ambulance Service.
But the threat has evolved and jihadist attacks like the one in Tunisia risk inspiring copycat action in Western countries, said Rosemont.
"There is concern in the UK around obviously individuals who may be inspired to take such action off the back of actions or activities or indeed propaganda by ISIS," he said, using another name for the Islamic State group.
Conservative Prime Minister David Cameron's government passed a Counter Terrorism and Security Bill earlier this year that includes measures to disrupt travel plans of British jihadists.
It is also planning to strengthen its legislative arsenal with a new law that would force mobile phone operators and Internet providers to hand over data about their customers to the police.
But the law, dubbed a "Snoopers' Charter" by the press, risks sparking outrage from those concerned about the power of the secret services following revelations about the US National Security Agency.
Gus Hosein, executive director of Privacy International, said: "This is a government that needs to be restrained, not rewarded with unrestrained and greater reach into our lives."