同袍赴国难 浴血护山河（山河显影）

Core Viewpoint - The July 7 Incident marked the beginning of the nationwide resistance against Japanese aggression, initiated by the attack on Chinese troops at the Lugou Bridge [2][4]. Group 1: Events Leading to the Incident - On the night of July 7, 1937, Japanese troops conducted provocative military exercises near the Lugou Bridge, claiming a soldier was missing and demanding to search the area, which was refused by Chinese forces [2]. - Following the refusal, Japanese forces attacked the Chinese garrison, leading to a counterattack by the 29th Army, thus igniting the national resistance [2]. Group 2: Response from Chinese Society - The incident sparked widespread outrage across various sectors of society, with calls for resistance against Japanese invasion rising nationwide [4]. - On July 8, the Chinese Communist Party issued a call for a united national resistance, emphasizing the need for a cohesive front against the aggressors [4]. - The Second United Front between the Chinese Nationalist Party and the Communist Party was established, fostering a broad coalition of various social groups and patriotic forces to participate in the anti-Japanese struggle [4].