In his declaration that “France is at war”, the French president, François Hollande, noted that this could not be a war between civilisations because the Islamic State (IS) movement does not represent a civilisation.

Strategic thinking is important. In the 1980s, despite an existential threat to the United Kingdom of greater magnitude than at any previous moment in its long history, this country navigated and concluded successfully the Cold War and managed the changes that were wrought to international relations thereafter. In the 1990s, Britain’s strategic success continued as it embraced the rehabilitation of two pariah states of the Cold War era, namely Russia and the People’s Republic of China. Moreover, Britain participated in the defeat of the naked aggression of Saddam Hussein’s Iraq in 1990-91, bolstering the hopes for a new world order based on global co-operation. Yet, in the early 2000s, a string of errors based on faulty assumptions, and an absence of strategy, became manifest in the military operations in Iraq and Afghanistan. We had apparently forgotten how to think strategically.