Another memory, from another atrocity, that of the bombings in the London transport system in July 2005, is of how despite the shock and surprise at what had happened, the truest fact was that it should not really have been a surprise at all. The much larger bombings the previous year at the Atocha Station in Madrid, which killed 191 people and wounded 1,800, should surely have taught us that.
A hasty, reflexive response is often the worst response of all. For France and for all of us in Europe, the real need is, first to grieve, but then to reflect upon what really matters in all our ability to deal with such acts of evil.
One principle is that such acts of war or of terror, call them what you will, know no borders. Only through collaboration and the sharing of intelligence and police-work can we increase our chances of preventing the next attacks.
A second principle, one that was rightly held dear after the Charlie Hebdo slaughter in January, is that far from giving up or compromising the very values of freedom and openness that are under attack, we must fight back by strengthening them.
The vast flow of refugees from the wars in Syria, Iraq, Libya and elsewhere in North Africa and the Middle East are heading for Europe because they value our values. We must never devalue them ourselves.
One of those values, built up patiently and painfully in the decades after 1945, has been our embrace of diversity and difference, our belief that a good, creative, lively society can and should be made up of many different minority groups. That was what characterized the Europe of the 19th century, and which two world wars served to set back, cruelly and brutally.
The European Union has been the means by which that value has been gradually rebuilt. The worst possible outcome of the Paris atrocities would be if any or all our countries went backwards again on that value, engaging in discrimination, recrimination, accusation and even ethnic cleansing.
It won’t be easy to hold the line on this. Public confidence in the security of European cities and in the very future of our continent is at a low ebb, damaged by the long economic crisis, by the divisions caused by the euro crisis, by the flood of refugees and economic migrants, and now once again by terrorism.
But the line does need to be held. All of us Europeans need to wake up to the value of what we have, in the face of the threats that surround us. We need to reflect calmly and soberly, and then to rebuild.