Western cities could face an onslaught of suicide bombers as Islamic extremists shift focus away from Iraq, a Midland terrorism expert has warned.
Dr David Carlton, senior lecturer in International Studies at Warwick University, said all major metropolitan areas - including Birmingham - were at risk.
Dr Carlton, whose book The West Road to 9/11 will be published in the autumn, claimed terrorists were hellbent on making "mass transport systems" unworkable.
And he warned there was little Western governments could do to stop them. "The tendency has been for suicide bombers to make their way to Iraq in order to break the American position in there," he said.
"Possibly they think blowing themselves up in large numbers in Iraq is bringing diminishing returns and therefore they are starting to hit the West and its metropolitan transport systems.
"I wouldn't want to say Birmingham is specifically vulnerable but obviously any large metropolitan area has to worry if there is a sustained attempt to make mass transport systems unworkable."
Dr Carlton claimed the London bombings were already part of a pattern of attacks on the West.
"It was the hijacking of planes that led to September 11," he said.
"Madrid is a case of transport being attacked. There have been attacks on Moscow underground. But it is now four years since September 11. You could not say these incidents are occurring daily or weekly, but perhaps we are seeing a pattern.
"It may be a slow escalating phenomenon. It may be Britain this week, Paris in six months and Rome in 12 months."
By highlighting weaknesses in the transport infrastructure, the attacks could have huge implications, he said.
"There are massive vulnerabilities in our transport system. There has been a big push
to bring security to the airlines, not without success.
"But when we take a plane flight it takes you a couple of hours to get through security. Imagine if that had to be done on the London Underground.
"This won't make that happen overnight, but if there was a series of attacks on mass transport systems the economic effect would be very severe because people would stop using them, leading to massive road snarl-ups.
"Or, they would insist on all bags on trains and buses being searched, which would make people's journey to work very lengthy."
Dr Carlton also questioned whether it would ever be possible to introduce such levels of security.
"Arguably it couldn't be done because of the volume of people it would need to administer," he said.
Yesterday's attacks are likely to smooth Home Secretary Charles Clarke's attempts to introduce ID cards in the UK, Dr Carlton added.
"The long-term measures that Mr Clarke is trying to get through becomes more do-able for the Government.
" Whether it would be enough against large determined groups engaged in hitandrun tactics placing a bag on a tube train or bus - I couldn't say we could really defend ourselves against this kind of tactic."