United States, By Rupert Cornwell in Washington
The apparently co-ordinated bombings in London have come as a stark reminder to Americans that terrorists are capable of striking anywhere in Europe, and presumably in the mainland US.
Michael Chertoff, the Homeland Security Secretary, said yesterday that the US had "no specific, credible intelligence" that similar attacks were imminent in the US. But the government's colour-coded alert system is being raised to its second highest level of orange for the country's mass transit systems.
Special attention is being focussed on five cities: Boston, New York, Washington DC, Atlanta and Miami.
Mr Chertoff said: "When we look at what happened in London, and the al-Qa'ida tactic of taking simultaneous action in several places, prudence and common sense dictates we take these measures." But he assured Americans that the authorities had already put extra precautions in place for public transport systems across the country since the Madrid commuter train bombings of March 2004.
Americans on the east coast learnt of the bomb attacks in London as they were preparing to go to work. For New Yorkers in particular the timing was an eerie coincidence, with the first bomb exploding shortly after 8.45am, almost exactly the same time of the day as the first hijacked aircraft smashed into the north tower of the World Trade Centre on 11 September 2001.
For President George Bush, the events in London are bitter proof of what he has long asserted: that terrorism is a constant, enduring threat, and that the "war" against it must continue, with unflagging vigour.
"We will not yield to these terrorists. We will find them, we will bring them to justice," Mr Bush told reporters at Gleneagles, where he is attending the G8 summit. "The war on terror goes on."
Last night, as a small team of FBI officials headed to London to help the investigation, US officials tried to determine the veracity of the claim by an al-Qa'ida cell that it was responsible for the London bombings, and were combing through the intelligence for clues that other attacks might be in the offing.
But the initial assumption here was that Islamic extremist terrorism was involved. Senior US counter-terrorism officials said that the attacks were well- co-ordinated and appeared sophisticated. They were consistent with known al-Qa'ida techniques, and similar to the Madrid bombings 16 months ago.
In fact, despite many alarms and attacks elsewhere in Europe, Asia and Africa, the US has been terrorism-free since the attacks in New York and Washington almost four years ago. Airport security has made a repeat of the 9/11 attacks all but impossible.
Hundreds of people, many of them of Arab or Middle Eastern origin, have been detained, while others, despite strong domestic and international protest, have been handed over to other countries under the procedure known as "extraordinary rendition".
Even so, yesterday's events in the capital that is Washington's closest ally in Iraq and the war on terror have increased fears of attacks in the US.
Counter-terrorism officials point to the years of preparation that went into 9/11, and warn that al-Qa'ida sleeper cells may well be plotting new outrages.
Although there are no specific indications of an increased terrorist menace to the US, security experts accept that further attacks in the US are all but inevitable. The fear now is that terrorists will shift from well-protected sites to soft targets, not only commuter trains and stations, but shopping malls, concerts and sporting events. Those worries would only be heightened if it transpired that suicide bombers carried out any of the London attacks.
The message then would be plain, that such a tactic could be just as easily be employed in Manhattan or Chicago as in Bloomsbury or the City of London. Officials add that in their next assault, terrorists might not use conventional explosives, as in Madrid or London, but chemical or biological agents, even a radioactive "dirty" weapon.
The still unexplained mailings of anthrax spores to buildings on Capitol Hill in autumn 2001 gave Washington an unsettling taste of possible things to come. Meanwhile, Jose Padilla, a US citizen, has been held since 2002 on the suspicion that he was examining potential sites for a "dirty bomb" attack in Washington or another major US city.
Nationwide, the US government's colour-coded threat level remains at the intermediate yellow level, in part because of widespread criticism that moving to a higher level causes unneccessary anxiety while providing few specifics.
The last occasion the threat-level as at orange was in August last year, after intelligence that al-Qa'ida operatives were targeting buildings in the financial districts of New York, northern New Jersey and Washington DC. It returned to yellow the following November.
In Washington, New York and Chicago, extra police, some of them with sniffer dogs, were visible, patrolling the cities' underground systems during the morning rush hour and beyond. Security was also stepped up on Amtrak, the national passenger rail network.
At the Pentagon, where 168 people died when the American Airlines jet smashed into the home of the Defence Department, police officers were out in force in squad cars, on bicycles and on foot, on nearby highways and at the local Metro underground station.
In Atlanta, all available commuter rail police officers and dogs were deployed. In Los Angeles, police officers were told not to leave their shifts without permission, while extra sheriff's deputies were sent to patrol Metrolink commuter stations and trains.
Russia, By Andrew Osborn in Moscow
Russia has been forced to live with the grim reality of terrorism since 1994, when Moscow first sent its troops into the southern republic of Chechnya to quell separatist sentiment there.
Since then Chechen extremists have consistently targeted ordinary Russians in a string of terror attacks designed to force the Kremlin's hand.
Their aim has been to achieve the complete withdrawal of federal troops and to win for Chechnya something it has thirsted after for centuries: its freedom.
Metro trains and stations, bus stops, airliners, apartment blocks, a theatre, a rock concert, a hospital and, most recently, a school have been targeted by Chechen gunmen and female suicide bombers known as "black widows".
Hundreds of innocent Russian civilians have died and many more have been wounded.
The Chechen extremists' precise motives remain shrouded in controversy. More moderate rebels say they merely want independence and "normal lives".
In recent years, such moderates appear to have lost considerable ground, however and, earlier this year, Aslan Maskhadov, the rebel Chechen president considered a moderating influence by some, was killed when Russian special forces got their man.
That left the stage to just one notorious Chechen warlord, the one-legged Shamil Basayev, Russia's most wanted man, who is on record as calling for a jihad or holy war to be waged across southern Russia. Indeed, rebel Chechen websites are awash with Islamist extremist slogans.
The Russian leader, Vladimir Putin, says Chechen extremists receive much of their funding from Saudi Arabia and has accused them of having close links with al-Qa'ida and Osama bin Laden himself.
Indeed, the Russian Army and the FSB security service regularly claim to have "liquidated" foreign fighters and mercenaries in Chechnya, and there are consistent reports that Chechen fighters have attended training camps in the Middle East.
According to the Kremlin, Basayev and his lieutenants want to set up an Islamist Caliphate in southern Russia, grouping together Chechnya and various other increasingly troubled regions. And to do so they will stop at nothing.
Without question, Russia's worst terrorist atrocity to date was the Beslan school siege in southern Russia last September when armed gunmen and female suicide bombers took more than 1,000 people hostage.
Some 330 people died, over half of them children, when the siege was finally broken and rebel gunmen traded fire and explosives with Russian troops.
The Dubrovka theatre siege in Moscow in 2002 also left a terrible scar on Russia's public consciousness. About 120 hostages and almost 50 Chechen extremists were killed when Russian special forces used a mysterious and powerful knock-out gas to recapture the theatre.
That was preceded by the seizure in 1995 of a hospital in southern Russia along with 1,000 hostages. Over 100 people were killed in the bungled commando raid that followed.
Such hostage crises have terrorised Russia over the years yet other attacks, mainly suicide bombings perpetrated by Chechen women whose own male relatives have perished in the Chechen conflict, have spread equal fear and panic.
The Moscow metro has been a frequent target. Last August a Chechen black widow blew herself up outside the Rijskaya metro station leaving 10 dead.
London's tragedy will therefore strike a horrible chord in Russia. "Welcome to our world," one Russian diplomatic source told The Independent yesterday.
"Quite scary, isn't it?"
Germany, By Tony Paterson in Berlin
Germany stepped up security on public transport and around British and American embassies in an immediate response to the London attacks as police called on the government to impose tougher measures to combat the terrorist threat.
Demanding tighter controls and stricter surveillance measures, the head of the German police union insisted: "The terror attacks on London are proof that Europe's capital cities remain under severe threat."
While active in the pursuit of terrorist suspects, the German government and security forces have yet to order London-style mock attacks in preparation for a possible terrorist onslaught.
The 11 September attacks on America were planned by Mohammed Atta, Marwan al-Shehhi and Ziad Jarrah while studying in Hamburg. But apart from the 1972 Munich Olympics attacks, post-war Germany's exposure to active terrorism has been limited to attacks by the former left-wing Red Army Faction (RAF), known as the Baader-Meinhof Gang, which waged war on the state and establishment in the 1970s and 1980s.
It attacked US Army bases in Germany, kidnapped and murdered several leading business figures and hijacked a Lufthansa jet to Mogadishu in the 1970s. But the RAF did not resort to al-Qa'ida style random attacks on the public at large.
Munich's closest experience to the London attacks was during the early 1980s, when a bomb planted by right-wing extremists was detonated at the city's October beer festival, maiming dozens of innocent participants. The 11 September attack and the subsequent discovery that the al-Qa'ida terrorists lived in Hamburg for several years as "sleepers" before moving to America to complete their mission, initially provoked condemnation from the US authorities and charges that Germany was soft on terrorism.
However, since then German police and intelligence services have adopted a much tougher approach to tracking down terror suspects. Over the past year, police have conducted a series of raids on suspected Islamic terrorist cells in the country. The last major raid was in January last year when police arrested 22 Islamic radicals suspected of aiding terrorism through money laundering and issuing of faked passports.
Yet while police have been successful in bringing suspects to court, the German judiciary has come in for criticism at home and abroad for failing to convict alleged terrorist offenders.
Italy, By John Phillips in Rome
The increasingly unpopular deployment of Italian troops in Iraq by the government of Silvio Berlusconi has left Italians nervous since the terrorist attack on a Madrid train in March last year in which 191 people died. Now the London blasts could cost the media mogul next year's general election, political sources say.
Like Germany, Italy had turned the page on two decades of domestic terrorism, by the left-wing Red Brigades and neo-Fascist gangs in the 1970s and 1980s. Although surviving members of the Red Brigades periodically carry out assassinations, they are a shadow of the organisation that rocked the state in 1978 with the kidnapping and murder of Aldo Moro, the Christian Democrat party president and statesman.
Nervousness in Italy's security services about a possible terrorist atrocity was evident at the 2001 G8 summit in Genoa where elaborate anti-aircraft defences were mounted. In the event, the only violence was between police and anti-globalisation demonstrators, one of whom was shot dead.
Since 11 September 2001, Italian police have rounded up scores of north Africans and Arabs suspected of being al-Qa'ida sympathisers and there is evidence that Naples, Milan and other cities have been used as transit points for Bin Laden supporters between north Africa and other parts of Europe.
The deaths of 17 Italian soldiers in a suicide bomb attack on their Iraqi barracks at Nasiriyah in November 2003 and a series of hostage crises culminating in the death in March this year of Nicola Calipari, an Italian intelligence agent shot by US troops after helping to release a journalist, Giuliana Sgrena, from kidnappers in Baghdad, have heightened public opposition to deployment of Italian forces in Iraq.
So did the disclosure by Italian magistrates last month that the CIA kidnapped an Islamic cleric, Abu Omar, in Milan and flew him to Egypt where he was reportedly tortured, a practice known as "extreme rendition". Mr Berlusconi's government denies it authorised the CIA's abduction of Abu Omar but public opinion remains sceptical.
Concern that Italy may be the next target after London could make Mr Berlusconi's policy of support for the US more unpopular though the wily Italian leader will no doubt seek to play up his official friendship with Tony Blair and the deep-seated Italian sympathy for Britain and all things English.
France, By John Lichfield in Paris
The Mayor of Paris, Bertrand Delanoe, put aside his disappointment at his city's failed Olympic bid to declare: "We are all Londoners now."
"The only thing that should concern us is the loss of life in a city which is our friend," he said as he flew in from Singapore. "Any other rivalry is derisory in light of these attacks."
There were similar reactions from President Jacques Chirac and the French Prime Minister, Dominique de Villepin. The French parliament suspended a sitting "out of respect for the dead and injured in London".
Despite the rift created by President Chirac's refusal to support the invasion of Iraq, France, the US and Britain have continued to co-operate closely in the hunt for al-Qa'ida. Last week it was revealed that the CIA and its French counterpart had a joined forces to track the activities of Islamist terrorists.
Paris was one of the first Western cities to experience terrorism at the hands of Islamist extremists, when a series of bombs was detonated at Metro stations in 1995. Those believed to be responsible were based in Britain, but the refusal of the British courts to allow the extradition of the man thought to be behind the blasts, currently being held in Belmarsh prison, has angered the French authorities.
The affair has been portrayed in France as a symptom of British laxity towards extremists. French anti-terrorist judges are also said to believe that - pre September 11 - there was a policy in London to turn a blind eye to Islamist activity so long as there was no direct threat to Britain.
Japan, By David McNeill in Tokyo
Ever since Junichiro Koizumi, Japan's Prime Minister, visited Ground Zero in New York in 2001, the country has been noticeably more jittery. Extra security has been put in place at every large organisation and new laws have been added to an already large array of anti-terror legislation.
When Japan sent troops to Iraq, straining the anti-war constitution to breaking point, it became a target for Osama bin Laden and his allies, who put Tokyo on their list of enemies.
Unlike Britain or Spain, Japan has no lingering separatist movements. It has the smallest foreign population of all G8 countries - including only 70,000 Muslims - and stringent entry controls. But the country's complacency was shaken last May when the police arrested five men from Bangladesh, India and Mali, and announced they were investigating a possible al-Qa'ida cell led by Lionel Dumont, a 33-year-old French Algerian.
Since Dumont's arrest, the authorities have cracked down on visa-less foreigners, an indication that Japan sees the threat as coming from overseas. But Japan's worst terrorist crimes have all been home grown.
Domestic ultra-rightists have murdered or attempted to murder several prominent politicians and, in Japan's most notorious terrorist incident, the religious cult Aum Shinrikyo used sarin nerve gas to attack the Tokyo subway in 1995, killing 12 and affecting thousands. Many of the cultists were graduates of elite universities who in another life might have gone on to work for the government.
Canada, By David Usborne in New York
Among all the G8 nations, Canada may seem most removed from the war on terror. Its reputation for neutrality and the absence of any attacks on its own soil since 11 September 2001 have added to the impression. But Canadian leaders take the threat of terrorism very seriously.
It is not just that Osama bin Laden has singled out Canada as one of a group of western countries his followers should seek to attack. There is also concern about terror cells operating, recruiting and training there.
Only this month a report from the Canadian Security Intelligence Service, leaked to the press, revealed how intense that worry has become. The agency estimates there may be as many as 40 terror cells plotting attacks.
The ease of movement between Canada and the US causes the Americans to look north with an anxious eye. Policing a border thousands of miles long is almost impossible. And memories are still fresh of the arrest of a terror suspect crossing to the US with a bootfulof explosives to attack Los Angeles airport on millennium eve.
Nor has Canada escaped terrorism. In 1985 a bomb exploded on an Air India jet that had taken off from Vancouver, causing it to crash into the Atlantic, killing 329 people, most of them Canadians. The government blamed Sikh extremists.
It is no wonder that the country's Communications Security Establishment, which listens in on suspects, has upped its budget by 57 per cent since 2001, or that Canada has passed emergency laws letting it hold terror suspects indefinitely without trial.Reuse content