"What the hell difference does it make, left or right? There were good men lost on both sides"

In this quote, Brendan Behan is revealing his disappointment and disbelief at the concept of choosing sides in a conflict. He questions the significance of being on the left or right side, as eventually, both sides have actually suffered losses of good males. Behan is highlighting the senselessness of war and the truth that it ultimately leads to the loss of innocent lives, despite which side they are on. He is also recommending that the labels of left and right are approximate and do not genuinely show the people involved in the dispute. Behan's words serve as a reminder to focus on the human expense of war rather than political ideologies.