I felt sure, glaring at the children as they settled onto the sand with their shovels, that these creatures were never threatened by the grimness of history, either. Then, looking down on their glossy heads, I realized that they were indeed threatened; they were simply unaware of it. We were all vulnerable.
The narrator observes children playing on the beach, noting their innocence and focus as they dig in the sand with shovels. This sight prompts a realization that, while they seem carefree, they are also at risk. The carefree nature of childhood contrasts sharply with the heavy weight of historical events, highlighting that vulnerability exists even in the most serene moments.
The passage reflects on the universal experience of being threatened by the harshness of reality, regardless of one's awareness. It emphasizes the idea that vulnerability is a shared human condition, and even in innocence, there is an underlying awareness of life's fragility, connecting the past's grim history to the present.