After 9/11, many European voices criticized the United States for passing the Patriot Act, which they felt sacrificed too many civil liberties in the name of cracking down on terrorism.
Now, one week after 7/7, European governments are wrestling with the balance between security and privacy as never before. And their efforts are giving new energy to counterterrorism cooperation.
In a flurry of activity this week:
• France announced plans to reintroduce border controls such as passport checks that were scrapped under the Schengen free- borders agreement with 14 other European countries.
• Italy announced closer monitoring of its northern border. And it detained 174 people suspected of being involved in Islamic militant groups. Italy's interior minister also asked parliament to expand police powers, including the right to question terrorism suspects without a lawyer.
• Germany drew up plans for a national antiterror database.
• In Brussels, meanwhile,British Home Secretary Charles Clarke called for better information sharing among law enforcement services and for redoubled efforts to stanch the flow of terrorist funds.
He also persuaded his counterparts to move ahead with plans to compel telecommunication firms to store phone and Internet records for possible intelligence use, saying the data would be vital to connect the dots of terror networks.
Analysts noted that some of these ideas had first emerged after the Madrid attacks in 2004, and said the long delay in implementation highlighted the problems of European counterterrorism cooperation.
Many added that they are skeptical at the new initiatives and nervous about sacrificing hard-won freedoms for the perception of extra security.
"This is a specific kind of ritual after every terror attack," says Rolf Tophoven, the director of the Institute for Terrorism Research and Security Policy in Essen, Germany. "After the shock we get this sudden activity on the political level on a huge scale. We get all these declarations that we have to make some new laws," he says. "Then, weeks later, you look and find every nation is acting by itself."
Though information sharing has improved between national police forces and intelligence agencies, experts say there is still room for greater cooperation, and that the national instincts of some services still preclude better collaboration.
"What does seem to make sense is that Europe needs real common investigations of these things rather than just sharing of intelligence against groups," says Dana Allin, an expert in European security at the International Institute for Strategic Studies in London.
"You're not going to have a European FBI," he concedes, "but these bombings are making people think seriously about European security as an EU-wide problem."
Efforts are hampered by differing judicial and political frameworks in each country. France, for example, has a centralized system, whereas Germany works on a more fragmented federal level. France has robust laws for detaining suspects and judges specifically trained to deal with the cases. Others do not.
And some countries, such as Italy, Spain, the Netherlands, and Britain, feel the need to step up efforts more urgently because they feel they are targets; other, smaller European countries that have no troops in Iraq or Afghanistan may feel measures are excessive for their needs.
Mr. Clarke said it was important, however, for a unified approach to logging data from mobile and Internet communications. The growing technological sophistication of the digital-era terrorist means that this data could provide pre-attack intelligence and post-attack evidence, officials argue.
Experts aren't so sure. "I'm not sure there is a demonstrable loophole that can be closed here," says one former intelligence officer familiar with European counterterrorism efforts. "They are saying they want access to records as preventive measures, which means you'd need access before the event. That really means surveillance."
Bob Ayers, a former US intelligence officer and managing director of Ayers and Associates, a consultancy, says: "As a citizen in a free society, I am troubled by the thought that governments will be monitoring communications patterns, even if the reason is a mass murder, a heinous crime.
"Once you've opened the door it's very difficult to understand where this surveillance will stop," he adds.
The European Parliament has already expressed concern about the proposals to force telecoms firms to keep traffic data for a year.
"It would be absurd to have mass surveillance while terrorists using pay-as-you-go phones or Internet cafes would escape detection," said Sarah Ludford, a member of the European Parliament.
"That is why many member states as well as the European Parliament are hesitant about overturning the general rule in EU law requires deletion of the data after a few months once bills are settled, and prohibits using data for purposes for which it was not collected."
But Clarke said questions of civil liberties had to be seen in the context of the 7/7 attacks, which killed more than 50 and injured more than 700.
"I argue that it is a fundamental civil liberty of people in Europe to be able to go to work on their transport system in the morning without being blown up and subject to terrorist attack," he said.
"We have to guarantee the fundamental right of security to citizens," said Franco Frattini, vice president of the European Commission after a two-minute silence across Europe for the victims of the London bombings. "It is a precondition for all other freedoms. If we are not free to go into the Underground, our society is not free."
France's move to restore border controls impinges on another cherished European liberty - the freedom of movement enshrined in the Schengen agreement, which came into force in 1995. Interior Minister Nicolas Sarkozy said the move was justified. "If we do not reinforce border controls when around 50 people die in London, I do not know when I would do it," he said.
Some experts assert that this is a freedom that Europe might have to learn to live without.
"We have to realize more and more that Schengen is a gift to terrorists," says Mr. Tophoven. "It's difficult to give it up, but if I were a terrorist, I would see the Schengen agreement as a gift."
Mr. Allin says he doesn't think Europe will sacrifice Schengen, but adds: "There is a mismatch between having effectively no borders and having police and intelligence services that still think in terms of national borders. That's an obvious problem."
Britain is poised to set the pace on fresh antiterror legislation. British Prime Minister Tony Blair will meet soon with opposition parties, Muslim community leaders, and security services to discuss stricter laws to curb terrorism.
And Clarke has begun an immediate review of powers he already has to exclude people from Britain who are inciting terrorism, a Blair spokesman said Thursday.
"We stand ready to give ... the security services any powers they need," the spokesman said..
• Material from wire services was used in this report.