In Chinese culture, 警惕 (jǐngtì) often reflects a collective and proactive approach to preventing problems before they arise. It is deeply embedded in the social fabric, from government slogans to parental advice. Phrases like “提高警惕，人人有责” (Tígāo jǐngtì, rén rén yǒu zé - “It is everyone's responsibility to raise vigilance”) are common in public campaigns concerning national security, public health, or fraud prevention. This concept can be contrasted with the Western idea of “being cautious.” While “being cautious” is often an individualistic and general piece of advice (e.g., “be cautious when investing”), 警惕 often implies being on guard against a specific, and sometimes external, threat to the group or nation. It carries a stronger undertone of defense and preparedness, rooted in a historical and cultural awareness that stability and safety must be actively maintained, not taken for granted. It's less about avoiding a simple accident and more about defending against a deliberate threat.
警惕 is used in both formal and informal contexts, but almost always with a serious tone.