‘When you’ve shouted Rule Britannia, when you’ve sung God Save the Queen, when you’ve finished killing Kruger with your mouth…’ So wrote Kipling derisively of the domestic cheerleaders of the Boer War. The lines came to mind this week as the Commons again strained at the leash of war. Horrified by the Aleppo atrocities, MPs dug deep into the jaded rhetoric of a superannuated great power.