The chemical weapons attack blamed on Bashar Assad’s regime must not go “unpunished”, Boris Johnson warned today. The Mayor of London also piled pressure on David Cameron to hold a second Commons vote to allow Britain to join military action against Assad’s forces. Just weeks ago, Mr Johnson told of his “deep anxieties” about the UK getting involved in the Syrian civil war in which at least 100,000 people have died. However, he said today: “But to use gas for mass murder is a crime that we cannot allow to go unpunished.” Writing in his Daily Telegraph column, the Mayor...