The argument over whether to fight in Libya had many aspects to it – ideology, national interest, diplomacy, military calculation. But the most important divide in the western world was temperamental. The Libyan debate pitted the hotheads against the ditherers. The leaders of the hotheads are Nicolas Sarkozy, president of France, and David Cameron, the prime minister of Britain. The ditherer-in-chief is Barack Obama, the US president, backed up by Angela Merkel, the German chancellor.

Mr Obama’s late decision to switch sides and throw America’s weight behind military action tipped the balance in favour of the hotheads and led to the UN resolution paving the way for war. But the divide between ditherers and hotheads still matters. This is the beginning not the end of the western-led intervention in Libya. With the Middle East in turmoil, further huge decisions loom. The temperamental divide between western leaders will continue to be crucial.

Hotheads, such as Mr Sarkozy, tend to be guided by emotion and gut instinct. They prefer short declaratory statements such as “this shall not pass” and “something must be done”. The hero of many hotheads is Winston Churchill. President George W.?Bush, the self-styled “decider”, placed a bust of Churchill in the Oval Office. Mr Obama had it removed.