Historian Gordon Johnson commented that "...Dyer's actions ran counter to Army regulations. These required that force should be constrained by what was reasonable to achieve an immediate objective; minimum, not maximum, force should be deployed. Moreover, proper warning had to be given. On 13 April 1919, as demonstrated by Collett, Dyer ignored this. While he may have believed the Raj was threatened, and may have thought the mob was out to attack him and his soldiers, this does not justify his cavalier abuse of procedure and his indifference to Indian suffering. In so behaving, he brought not only death to the innocent but also destroyed himself and undermined the empire in which he took so much pride."