Despite all attempts, it's still hard to smoke out the bad guys

Did Osama bin Laden sit up in his watery grave as the drama of the Boston bombing unfolded? Was that noise a rattling of bones or a self-congratulatory chuckle as he watched Americans proclaim their resilience - at the same time as one of the biggest cities in the country was ordered into an extraordinary lockdown?

And for all the efforts to have greater co-operation among US security agencies in the wake of the September 11 attacks, information emerging in the aftermath of the April 15 attack on the crowded finishing line of the Boston marathon reveals they still have difficulty "connecting the dots".

Despite a Russian tip-off, first to the FBI and later to the CIA, the American agencies could not keep the ringleader Tamerlan Tsarnaev off the streets and away from explosives, much less on their collective radar.

Although the 26-year-old's six-month stay in the restive Russian provinces of Dagestan and Chechnya last year appears central in his radicalisation, the agencies were aware only of his departure from the US - and not of his arrival back in the country. After he arrived back, he set about devising a plot which, by the time of his death in a police shoot-out and the arrest of his accomplice, younger brother Dzhokhar, had killed four people and injured more than 250.

The information-sharing breakdown was due, in part, to the misspelling of the older Tsarnaev's name on an airline manifest. In all of this there is a sense that although the agencies could not see where to go, they sensed that Tamerlan Tsarnaev was a problem.

In response to the Russian tip-off, the FBI interviewed him and others in his family - "but did not find any terrorist activity - domestic or foreign," the agency said in a statement. That OK by the FBI made Tsarnaev the fifth person since 9/11 to be part of a big terror plot after questioning by the FBI.

And although the CIA's checks produced the same result as those by the FBI, the CIA did request that the National Counterterrorism Centre take the precaution of adding his name to its watch list.

The State Department and Homeland Security were notified - and Homeland Security was sufficiently alarmed that it baulked at authorising a citizenship application by the older brother.

Even though there was no Russian response to a specific request for more information, the FBI also acted to have Tsarnaev's name added to another watch list - the Treasury Enforcement Communications System, which sends an electronic signal to customs officials when anyone whose names are on the list leave the country

Despite the hugely greater success in dealing with terrorist cases in US criminal courts, President Barack Obama has had to stare down Republican calls to go the Guantanamo route, for the surviving younger brother to be declared an "enemy combatant".

That push provoked contempt from Harvard law professor Alan Dershowitz: "It shows a complete and total ignorance of the US constitution. This is an American citizen being charged with committing a crime on American soil against Americans."

Government prosecutors have earned almost 500 terror-related convictions in US criminal courts since 9/11 - compared with just seven that have been achieved in the controversial and slow-moving military commissions at Guantanamo, where about 800 inmates have been processed.

Then came the knee-jerk calls for increased surveillance of Muslims and mosque communities and a tightening of immigration laws that likely would derail what, till the day of the Boston marathon, had been a package of reforms to address the legal status of millions of undocumented migrants - for which there had been broad bipartisan support.

When census data is factored into the debate, lashing out at immigrants and/or Muslims doesn't make sense - more than 12 per cent of US residents are foreign-born; and there are almost three million Muslims in the country.

As far as radio loud mouth Rush Limbaugh was concerned, Boston deserved what it got from the Tsarnaevs because, "It's a hubbub of liberal elite intellectual thought, all the universities there."

Using President Obama's declaration that "Americans refuse to be terrorised" as his starting point, University of Michigan anthropologist Scott Atran wrote: "Never in history have so few, armed with so few means, caused so much fear in so many ... the response [in Boston] is precisely the outsized reaction that sponsors of terrorism have always counted on in order to terrorise.

"What we already know about the April 15 bombing does not justify the disproportionate and overwrought response, including the 'global security alert' US authorities issued through Interpol for 190 countries," Atran said.

The liberal columnist Michael Tomasky argued that a common thread to the conservative reaction is a need to instil and maintain a level of fear. "They need to make gun owners fear ... SWAT teams are going to come knocking on their doors ... or that they have to be armed to the teeth for that inevitable day when the government declares a police state," he wrote at the Daily Beast.

But if the authorities and the media were being judged to have gone overboard, polling indicated that while most Americans believed future attacks were quite likely, they did not feel threatened personally and they were inclined to be sceptical about curbing personal freedoms for the sake of security.

There is, after all, a practical element to what can be done. Phillip Mudd, a former CIA and FBI counterterror analyst, cautioned that the consequence of a broad misunderstanding of what would be required for detailed action on all tip-offs to the authorities would require turning the US into a "surveillance state".

"During daily threat briefings, we'd look at home-growns all the time," he told reporters. "The question is: what kind of screening do you want in place to get an American [suspect] into that lens? Before you want to swing that pendulum too far, be careful.

"There's only so much you can do in an open society to penetrate a closed circle. How are you going to boil the 10,000 people you interview down to that one case, and how are you going to deal with the 500 false positives?"

Atran said overreaction to sporadic terrorist acts has turned "the somewhat marginal phenomenon of terrorism" into a primary preoccupation of the US government and American people".

"In this sense, Osama bin Laden has been victorious beyond his wildest dreams - not because of anything he has done, but because of how we have reacted to the episodic success he inspires."