Juliette Kayyem, who among other things is a security consultant:

But what if the essence of a place is that it is defenseless? What if its ability to welcome others, to be hospitable to strangers, is its identity? What if vulnerability is its unstated mission? That is the challenge I hadn’t considered….

In security, we view vulnerabilities as inherently bad. We solve the problem with layered defenses: more locks, more surveillance. Deprive strangers of access to your temple, I urged the committee members [at Tree of Life Synagogue in Pittsburgh], and have congregants carry ID. They would have none of it. Access was a vulnerability embedded in the institution, and no security expert could change that — we do logistics, not souls.

The standoff in Colleyville ended with the attacker dead and the hostages unharmed. But all around the country, synagogues are no doubt convening their security committees, wondering what more they can do to defend their members without losing their essential vulnerability. A synagogue is not like an airport or a stadium. When it becomes a fortress, something immeasurable is lost.