British Prime Minister Keir Starmer said on Monday he would quit, paving the way for the country to have its seventh leader in 10 years. The chaos dates back to the Brexit referendum, 10 years ago to the day on Tuesday. In the years since the vote, Britain has tried to forge its own path but struggled to boost its low-growth economy, hamstrung by high debts and a growing welfare bill, at a time of growing geopolitical volatility.