Thoughts on Sassoon's declaration

In this declaration Sassoon shows his bravery in many different ways.
The first being his will to confront the military head with his honest opinions while knowing this may lead to him being court-martialed or even executed. We could believe here that with the horrors he has seen the importance for his life has no more meaning to him, as if saving his comrades from this war was more important/bigger than his own life. This can be seen as very left-wing.
The second being the fact that he latched out from normal society standards for the common English Gentlemen. He expresses revolt against his authorities and he expresses fear, something rather taboo for the men of that age. However he continues and not only talking about himself but about his fellow soldiers as we can see in "I am acting on behalf of soldiers". His bravery is proven as his friend Graves tries to protect him by convincing the military that he is suffering from shell-shock and is not in control of his mind. His bravery is proven because even his close friend does not dare speak out as he does against the war.