What violent event occurred as a result of an assassination attempt on Lenin in August 1918?

The assassination attempt on Lenin in August 1918 prompted the Bolshevik government to initiate the Red Terror, a campaign of political repression aimed at consolidating power and defending the revolution against perceived enemies. This violent backlash involved widespread arrests, executions, and the establishment of the Cheka (the secret police) to eliminate opposition and dissent. The Red Terror represented a significant escalation in state violence as the Bolsheviks sought to secure their hold on power during the tumultuous period of the Russian Civil War. This reaction was rooted in a context where the Bolsheviks faced both internal and external threats, leading to the justification of extreme measures to protect the revolution and the party's leadership.

The other options do not directly relate to the immediate consequences of the assassination attempt. The execution of the Romanov family occurred later in July 1918 and was part of a broader context of eliminating the old regime. The formation of the Czech Legion was a response to the war and the Russian Civil War, but it was not a direct result of Lenin’s assassination attempt. Lastly, the lifting of the War Communism policy occurred later as the Bolsheviks tried to stabilize the economy and counteract the negative effects of their previous policies.