Both attacks hit so-called "soft targets," designations that describe people or things that are relatively unprotected or vulnerable. These targets include public places many people visit every day. Places like the promenade in Nice and the Christmas market in Berlin.

When I think about a Christmas market, I usually think about candy canes, coziness, twinkle lights, and "All I Want for Christmas" playing on repeat. The holiday traditions are symbols of community. The young and the old, tourists and locals, families and friends — you can meet all kinds of people there. But this morning, the term conjures feelings of loss and sorrow.

The whole time I spent in France, there were soldiers with machine guns in groups of three on the street and at the stations. They waited in front of museums and theaters. I had to let them check my purse when I wanted to get in. Now, people are asking why German Christmas markets haven't been protected more strictly.

"That was so predictable. They do not want us to have peaceful Christmas,” my French friend wrote to me yesterday. I tried to stay calm since the circumstances of the incident weren't really cleared up at that time and there was still the chance that it was all a tragic accident. Today, authorities confirmed that they believe it was no accident. The shock is deeply felt.

But I learned one important lesson from what I've experienced in Nice, and now, Berlin: We must not let fear guide our hearts in the wake of such terrible events. We must go out there and stay strong.

In times like these, solidarity and community are crucial forms of support. We must stay together, united for peace. There is no room for hatred and fear. The general suspicion of certain ethnic and religious groups is as useless as it is misguided.

From my own experience, I can say that while it won't be easy, it is important to go on. Otherwise, the assassins will achieve their goal: societies living in fear.

In trying times like these, our mantra must be, No fear, no hatred.

Translated by Anna Hackbarth