Not all security happens in the dark. A lot of it happens in plain sight. In military barrier airport security, we use physical barriers as a psychological tool. We want potential attackers to look at our installations and think, "This is too hard. I'll go somewhere else."

It’s a simple concept, but it’s incredibly effective. When someone sees a massive, reinforced concrete wedge blocking a road, they understand the message immediately. They know that trying to bypass it is a suicide mission.

I’ve talked to security directors who say that upgrading their visible barriers actually reduced the number of minor trespassing incidents. People just don't test the perimeter when it looks impenetrable.

But we have to be careful. We don't want to make passengers feel like they are entering a war zone. The barriers need to look professional and controlled, not aggressive and scary. We use clean lines, modern materials, and sometimes even landscaping to soften the look while maintaining the strength.

I remember a project where we replaced an old, ugly chain-link fence with a sleek, anti-climb mesh backed by concrete bollards. The complaints from the public stopped immediately. It looked like a modern facility, not a fortress.

Security is a feeling as much as it is a physical reality. When we design barriers, we are designing a feeling of safety for the passengers, and a feeling of dread for the attackers. Getting that balance right is what I love about this job.