The recent terrorist bombing at Kabul airport that killed more than 100 Afghan civilians and 13 US troops has added more horror to an awful summer. It also shows that Voltaire was not always correct. An enthusiastic gardener, he occasionally gave the impression one could forget about the world’s troubles by weeding a herbaceous border or strolling through an orchard. No such luck these days, alas, even on holiday in August.

When I am at my summer home in rural France, I look at the beautiful white-flowered rose—a Kiftsgate, native to western China—that envelops the entrance arch. I once saw an even more magnificent specimen. It covered the wall of the presidential palace in Kabul, which I visited in 2003 as a European Commissioner to help put in place the European Union’s development program in Afghanistan after the Western military intervention there to rout al-Qaeda.

Today, practically all we hear about Afghanistan is the grim news of the chaotic retreat from the country by the West, and particularly the United States. It has come as a great surprise to many that US President Joe Biden carried out Donald Trump’s strategy of quitting Afghanistan after 20 years, although Biden postponed the withdrawal of American troops by about three months.

Biden had long been a critic of the US military commitment in Afghanistan, even though it had been scaled back significantly in recent years. But why he thought a hasty troop withdrawal was a good idea is something of a mystery, not least given the quality of his advisers and his own international experience. The most plausible explanation is that Biden believed following Trump down this dishonourable path could recover some of the working-class support that the Democrats had been losing to Trump’s isolationist populism.

True, Afghanistan has a well-deserved reputation for being a political graveyard as well as a real one. The former UK Prime Minister Harold Macmillan, drawing on the experience of three fairly disastrous interventions by British imperial forces from India in the nineteenth and early twentieth centuries, once said that the first law of politics was not to invade Afghanistan. The Soviet Union learned a similar lesson in the 1980s in a nine-year war that caused huge loss of life and destruction in Afghanistan, killed 15,000 Soviet soldiers, and contributed significantly to the collapse of the USSR itself.

Despite these historical reasons for showing the greatest possible caution vis-à-vis Afghanistan, the Western intervention following the al-Qaeda terrorist attacks against the US in 2001 went far toward fulfiling its main purpose of making North America and Europe safer from Islamic terrorism. By 2003-04, Western forces and development assistance were starting to stabilise life in Afghanistan and even partly curtail the illicit drug trade, a principal source of terrorist funding as well as rural income.

These efforts were accompanied by much well-meaning rhetoric about how humanitarian intervention by rich open societies could make the world safer. But, unsurprisingly, this commitment began to fray and buckle, largely as a consequence of the Iraq War, a huge error that created far more chaos than it prevented. What started as an advertisement for humanitarian intervention discredited the concept.

Tony Blair, the former UK prime minister who has criticised Biden’s Afghan policy as “imbecilic,” should recognise that many think his own enthusiastic support for the Iraq War was even more imbecilic. That conflict drained political energy and resources from Afghanistan and thus made completing the West’s task there far more difficult.

The damaging shambles of the Western retreat from Afghanistan holds lessons for all of us. First, the entire international community has an obligation to save the Afghan people from a humanitarian catastrophe and provide refuge for those who wish to flee the country for political reasons. If we can restrain the Taliban in any way, which appears doubtful, we need to do so with as much support from Afghanistan’s neighbours as possible.

For the US, the main lesson is clear. When Biden told the world in February that “America is back,” many assumed he meant the US would lead an alliance of open societies determined to stand up for the rule of law and an international order promoting peace and prosperity. But if “America is back” instead means that the US is returning to isolationism, the result will be bad for everyone, including Americans.

As has been the case since World War II, America remains indispensable to a peaceful and prosperous world. That means its allies need to be able to have faith in its commitments. The same is true of those whose peaceful self-determination America has promised to guarantee—including, for example, Taiwan and Ukraine.

The EU, for its part, must ask itself whether it is willing and able to give greater assistance to the US in its leadership role. Europe cannot go on piggybacking on the US security guarantee while carping that America does not do even more.

Britain, having cut itself adrift from the EU to stake its claim to global relevance, must face up to the fact that it does not count for much when the US decides what it wants to do. As former Prime Minister Theresa May recently asked her successor, Boris Johnson, in Parliament, “Where is global Britain on the streets of Kabul?” Johnson finds himself distrusted in Brussels, Paris, and Berlin, and neither trusted nor taken seriously in Washington. Despite Brexit, he needs to rebuild his relationships in Europe, and soon.

All these issues need to be confronted imaginatively. If we—above all, the US and Europe—fail, then the cause of liberal democracy in the twenty-first century could go the way of Afghanistan.

—Project Syndicate