The power system, as vital national infrastructure, is confronted with increasingly severe external attack threats. Current research has primarily focused on defensive layouts and loss analyses in the context of specific attack levels, neglecting the unpredictability of attacker's capability and lacking an endurance safety assessment for the power system. Compared to mainstream studies, the work reported in this paper presents a novel analytical scenario where a regional power system experiences complete failure due to the physical attack, aiming to develop a holistic vulnerability assessment ...