If the goals were fear, outrage and despair, the target was well chosen. Monday’s attack on a German Christmas market took place in the heart of the national capital, during a celebration of the Christian season of peace, and at the foot of the Ged?chtniskirche, symbol of Germany’s postwar rebirth as a free and democratic republic. The truck that smashed through the market killed 12 people and left scores hurt. This is terrible enough. But the values of which modern Germans are justly proud also took a vicious blow.

To the extent that terrorists have a strategy — and are not simply servants of rage and bloodlust — they aim to provoke a response that makes their target appear to be the enemy of the oppressed, or those who would posture at oppression. This leaves Germany, Europe and the west with hard choices. The murder of innocents stirs strong emotions but a vengeful reply is the validation the terrorist seeks. The fact that the Berlin attacks took place on the same day as attacks in Switzerland and Turkey, and the day after one in Jordan, will amplify this effect. At the same time, inaction is dangerous, too, and a political impossibility.

German Chancellor Angela Merkel, who faces an election next year, is already under pressure from her right wing because of her decision last year to let in more than 1m refugees, many from Syria. A leader of the conservative Christian Social Union party urged a “fundamental rethink of how our refugee policy works” if the attacker — who may still be at large — was an asylum seeker. A leader of the hard-right Alternative for Germany went further: “These are Merkel’s dead!”, he tweeted.