Metropolitan Police Commissioner Sir Ian Blair has said another terrorist attack in London is inevitable.
He said the force had since foiled three further attacks but the strength of Londoners meant the city would survive future assaults.
He said the much criticised anti-terror raid in Forest Gate last month had been his lowest point since the bombings.
Sir Ian was speaking on the first anniversary of the 7 July bombings, carried out by four men from Yorkshire.
He said: "I think there will be further attacks, in fact I know there will be further attacks.
"We are doing all we can to stop those, we have stopped three already."
But Sir Ian said: "No matter how dreadful the terrorists are, it is infinitesimal compared to the strength of Londoners.
"Today on the anniversary my main feeling is pride. Pride in London - the city reacted brilliantly to the events of last July - and pride in my force and the other emergency services.
"We decided we weren't going to let the terrorists win and there was very little real rise in the number of racist attacks, which I think shows a city which is confident in itself."
Sir Ian defended June's raid in Forest Gate, east London, in which two brothers were held and then later released without charge
He said: "I have not met a single person inside my organisation who said you should not have gone in there.
A bus was blown apart in Tavistock Square
"We cannot do nothing when we have credible intelligence saying someone is planning an atrocity.
"There will be further anti-terror raids but there should also be a mechanism for engaging Muslim leaders about the intelligence we have before going in."
He also reiterated his appeal to the Muslim community to help stop further terrorist attacks.
"It is not the police or the intelligence services that will defeat the terrorists," he said.
"It is the communities. They must be our eyes and ears on the streets and tell us about their concerns."
Meanwhile, another chief constable has admitted future attacks are "very possible".
Colin Cramphorn, Chief Constable of West Yorkshire Police, said: "Those attacks may be local, they may be further afield in the UK or they may indeed be focused on other parts of the world."