But beyond the immediate panic and horror, there also appears to be a potentially more pernicious reward to the forces of the political far right best positioned to capitalize on such a tragedy.
Indeed, the domestic political fallout of both incidents promises to carry far beyond the borders of Germany or France, spreading a radical shift to the right that holds the potential of upsetting not only the ruling elite, but the very glue that holds Europe together.
Even while Sven Gerling, a spokesman for the Berlin fire service, was saying
, "We are at the scene with a large number of vehicles. The police are too. We are trying to save a number of lives," a spokesman for Chancellor Angela Merkel was assuring the nation that she was being briefed by her interior minister and by the mayor of Berlin.
As police began to dig into the background of the truck's driver, however, it was clear that Merkel would have to do some neat pivoting if she was to win a fourth term as chancellor.
Ironically, it was just one month ago that she announced
she would stand for re-election. Even then, she was facing some tough challenges -- particularly from the Alternative for German (AfD) Party and its fiery leader, Frauke Petry, who have already launched a vicious, and in scattered local contests
, successful campaign.
They claim that Merkel has been far too generous and accommodating in welcoming refugees from the Middle East, at least some of whom intend to harm the nation that has been so generous in opening its doors to them.
As long ago as January, Petry was urging German border police to shoot
on the spot any refugees found entering Germany illegally. The fear is that to match such rhetoric in the face of the post-Christmas market massacre, Merkel will have to edge farther toward the right.
Already, she did a bit of a pivot two weeks ago when she called for a ban on wearing a veil in public. "The full veil is not appropriate here. It should be forbidden wherever that is legally possible. It does not belong to us," she told
a Christian Democratic Union (CDU) gathering.
The fact is, across Western Europe there is a full-scale assault on traditional democratic values that many are increasingly coming to fear are only giving aid and comfort to the kinds of jihadists prepared to seize on any leniency to drive their trucks into crowds of innocents enjoying themselves.
In France, the fears that sprung from a succession of terrorist attacks over the past year played a central role in hammering the popularity rating of Francois Hollande into the single digits and driving him from a re-election bid, while strengthening the hand of anti-immigrant, anti-Muslim, far-right leader Marine Le Pen of the National Front party.
In Italy, similar concerns led to the ouster of Italy's center-left politician, while in Austria the far-right candidate managed to get into a two-way run-off for his nation's presidency. The new, populist government in Poland has already shifted far to the right, and other nations including the Netherlands, Norway, Hungary and even Liechtenstein are set to hold their own elections in 2017 alongside France and Germany.
Across Europe, right-wing candidates are positioning themselves against immigration and Islam, defending an ever-tougher stance with every new terrorist assault.
A broader fear, though, is that terror incidents that pose electoral challenges for some of Europe's leading pillars of unity like Merkel could provide ammunition for right-wing leaders who want to go beyond simple bans on immigration from the Middle East. The AfD, the National Front and their supporters want nothing less than a dissolution of the European Union and a return to pull-up-the-drawbridge nationalism for their individual nations.
Brexit was only the first example of this kind of political mentality. The thousands of immigrants from the Middle East clamoring for entry to Britain only stoked the fires of exiting the European Union.
Each successive, successful and bloody terrorist attack will further whet the appetite of right-wing politicians and their supporters, feverish to return full control over their nation's security to their own security forces.
This is the ultimate danger of terror attacks. Reasonable men and women must recognize them for what they are -- an effort to drain what is left of democracy from our nations. As President-elect Donald Trump begins to focus on how to respond, he should understand that support for moderation and unity will defeat those who prefer to divide each of us. A populist agenda, in contrast, will only strengthen and embolden our enemies.