Given the size of the Moscow Metro, the authorities must have known it was a potential target
By Richard Galpin
BBC News, Moscow
The initial statement given by Russian President Dmitry Medvedev following Monday's double suicide bombings in Moscow is instructive.
Predictably, he repeated the usual mantra that the fight against militants in the North Caucasus will continue "to the very end".
But he also appeared to criticise the police and security services, saying there was a "need to strengthen considerably what is being done" in terms of providing security for the country's transport systems.
The carnage in the Moscow Metro will not have come as a complete surprise to the Russian authorities.
Back in November, Islamic militants based in the Northern Caucasus claimed they were behind a bomb attack which derailed a luxury train travelling between Moscow and St Petersburg, one of the country's most important routes. At least 26 passengers were killed.
The claim was made in the name of the self-styled leader of the Islamist rebellion in the North Caucasus, Doku Umarov.
And if this was not enough to make it clear that the rebels were extending their reach once again beyond the North Caucasus region, then just last month, Doku Umarov issued an explicit warning saying they were planning to target towns and cities in mainland Russia.
In an interview posted on the internet on 14 February, he said he wanted to show the Russian people that the war in the Caucasus was not just something "they could watch on television".
Given the size of the Moscow Metro, the number of people who use it and the history of previous militants' attacks on this iconic transport system, the authorities must have known it was a potential target.
So what has happened is an embarrassing lapse of security by the police and intelligence services.
One senior security analyst told the BBC the authorities had simply not expected to deal with this kind of threat by individual suicide bombers.
It is also damaging for the country's top politicians including Mr Medvedev and Prime Minister Vladimir Putin.
Last year, there was much fanfare surrounding an announcement that the Chechen rebels had been crushed and the second Chechen war was officially at an end.
There was talk of Chechnya now being able to attract foreign investment and even becoming a tourist destination.
But in fact, the rebels in Chechnya were never fully crushed and the insurgency had spread to other regions, including Ingushetia and Dagestan.
There is now a small hardcore of militants operating across the region with the declared goal of creating an Islamic caliphate.
And they have proved they are capable of striking in the heart of the capital, Moscow.
For the population in Moscow and the other major towns and cities, the big worry is that this is just the start of a new wave of attacks.
And the question for the government is how to react.
One thing has been made clear by Monday's bombings: the intelligence services are not getting the information they need to prevent atrocities in which civilians are the victims.