The phrase implies continuous attention and watchfulness over a period.

Constant Vigilance

It's a figurative expression meaning to be attentive, not to literally watch something non-stop.

Not Literal

Using this phrase often suggests that there might be a risk or issue to be aware of.

The phrase suggests staying alert to react quickly to changes or problems.

It can indicate discreet surveillance, often to prevent unwanted actions.

It's often used to suggest tracking the development or process of something continually.