A sudden lack of confidence in his security measures?

However, the girl is puzzled by this sudden lack of attention; it seems like mom's pushing her away.

The sudden lack of resistance made him stumble as she went down.

You say it is not his sudden lack of a fortune.

But it was the sudden lack of fear that made him wary.

He knew at once from her sudden lack of expression that she was not going to answer.

She saw the same sudden lack of certainty in his dark eyes that she'd felt a moment before and took pity on him.

The sudden lack of sound was worse than just silence.

She had detected an eagerness in the man's voice, and it made her feel a sudden lack of security.

It was a few moments before their eyes became accustomed to the sudden lack of light.