What has defined the 21st century so far?
Eight shocks that made the world we live in — from the dot-com crash to Gaza. What happened, how — and the shockwave that never stopped.
Last updated: October 2026
The century is a quarter done and it has already rewritten the rules several times over. These eight reports trace the shocks in order — money, war, money again, revolt, a moving border, terror, plague, and Gaza — each signed by one of our correspondents, writing as a historian: facts, zero slant.
The century began with a shock that set its tone. On 11 September 2001, the Al-Qaeda network hijacked four passenger aircraft and flew two of them into the twin towers of the World Trade Center in New York, one into the Pentagon, and a fourth into a field in Pennsylvania after passengers fought back. Nearly three thousand people were killed. The United States, under President George W. Bush, declared a war on terror, invaded Afghanistan in 2001 to remove the Taliban regime that had sheltered Al-Qaeda, and invaded Iraq in 2003 on the claim that Saddam Hussein possessed weapons of mass destruction — a claim that proved false. Both wars lasted far longer than their planners expected: the Afghan war became America's longest, ending only in 2021 with the Taliban's return to power.
The wars reshaped the politics of the West and the Middle East alike. The Iraq invasion, opposed by France, Germany, and Russia among others, damaged the transatlantic alliance and fuelled a generation of grievance that fed new extremist movements, above all the Islamic State group, which seized territory in Iraq and Syria in 2014 and carried out attacks in Europe. The killing of Osama bin Laden by American forces in Pakistan in 2011 did not end jihadist terrorism, and the wars left hundreds of thousands of people dead and millions displaced. The century's first lesson, if it has one, is that military power can topple regimes far more easily than it can build what comes after.
The second great force of the century has been connection. When the century opened, the internet was still a desktop affair and the mobile phone was a device for calls. Apple's iPhone, launched in 2007, put a computer, a camera, and the internet into a pocket, and the smartphone spread to billions of people within a decade. Social media platforms — Facebook, YouTube, Twitter, Instagram, WhatsApp, TikTok — gave ordinary people the power to publish, organise, and broadcast, and gave companies and governments new ways to watch, persuade, and manipulate them.
Connection has been both liberation and disruption. Social media helped protesters organise during the Arab Spring of 2010 and 2011, when uprisings toppled rulers in Tunisia, Egypt, and Libya. It also spread misinformation at a speed no censor could match, deepened political polarisation, and gave authoritarian states tools of surveillance of unprecedented precision. The same networks that carried revolutions carried conspiracy theories, and the same platforms that connected families became arenas for harassment and foreign influence operations. The century's defining technology has not settled the argument between freedom and control — it has made the argument faster, louder, and global.
Money has twice rewritten the century's politics. The first shock came in 2008, when the collapse of the American housing market and the failure of the Lehman Brothers bank triggered a global financial crisis. Banks were rescued with public money; millions of people lost homes, jobs, and savings; and the eurozone was plunged into a sovereign debt crisis that nearly broke the single currency. The crisis discredited the financial establishment and fed a populist anger that would reshape politics on both sides of the Atlantic: the Tea Party in the United States, anti-austerity movements in Europe, and a general suspicion that the system was rigged.
The second shock was economic too, but of a different kind. The COVID-19 pandemic of 2020 forced governments to shut down much of the world economy, then to spend on a scale not seen since the Second World War to keep households and firms alive. When economies reopened, disrupted supply chains and the war in Ukraine pushed inflation to levels not seen in forty years, and central banks raised interest rates sharply. By 2025, the era of cheap money that had defined the 2010s was over, and governments everywhere were grappling with higher debt, higher prices, and a public that had lost patience with economic promises.
The century has been an age of revolt, and of revolt's limits. The Arab Spring began in December 2010, when a Tunisian street vendor, Mohamed Bouazizi, set himself on fire after being humiliated by officials, and protests spread across the Arab world. Tunisia's ruler fled; Egypt's Hosni Mubarak fell; Libya's Muammar Gaddafi was killed after NATO intervened. But Syria's protests became a civil war that killed hundreds of thousands and displaced millions, and Egypt returned to military rule. The hopes of 2011 curdled into the lesson that removing a dictator is easier than building a democracy.
In the West, revolt took the form of populism. Britain's 2016 referendum voted to leave the European Union; the United States elected Donald Trump the same year on a promise to put America first; and populist parties gained ground across Europe, from Hungary and Poland to Italy and France. Scholars argue over the causes — economic insecurity, cultural backlash, the failures of mainstream parties — but the pattern is clear: the century's third decade has seen a broad challenge to the liberal order that followed the Cold War, and the outcome of that challenge is still undecided as of 2025.
In early 2020, a new coronavirus, SARS-CoV-2, spread from China around the world in a matter of weeks. The COVID-19 pandemic killed millions of people, shut schools and borders, emptied cities, and forced a global experiment in remote work and online life. It also produced a scientific triumph: effective vaccines were developed, tested, and manufactured within a year, a speed without precedent. But the pandemic also exposed deep inequalities — in access to vaccines, in the ability to work from home, in the resilience of health systems — and it left a legacy of distrust, debt, and grief that still shapes politics.
Behind the pandemic sits a slower, larger force: climate change. The century has been the warmest on record, and its weather has carried the signature: record heatwaves, wildfires from Australia to California to the Mediterranean, floods, and storms of growing intensity. The 2015 Paris Agreement, in which nearly every country pledged to limit warming, was a landmark of diplomacy, but emissions continued to rise for years afterward. The energy transition — solar, wind, batteries, electric vehicles — has advanced faster than most experts predicted in the 2000s, led in manufacturing by China, and the contest over who pays for the transition, and who benefits, has become one of the century's central political fights.
In February 2022, Russia launched a full-scale invasion of Ukraine, the largest war in Europe since 1945. The invasion shattered the assumption that great-power war in Europe belonged to the past, revived NATO, drove Finland and Sweden to join the alliance, and sent energy prices and grain supplies into turmoil. In October 2023, the Hamas attack on Israel and the war in Gaza that followed killed tens of thousands of people, polarised the world, and raised the question of whether the international order could still restrain war at all. As of 2025, both wars continued, and the century's map of power — the rise of China, the assertiveness of Russia, the strains on the American-led order — looked more contested than at any point since the Cold War.
The century's newest force is artificial intelligence. Machine learning systems, trained on vast quantities of text, images, and data, began to match or exceed human performance in narrow tasks in the 2010s, and the release of ChatGPT in late 2022 brought conversational AI to hundreds of millions of users within months. AI now writes, codes, diagnoses, and designs — and it has raised questions that the century's earlier technologies did not: about work, creativity, truth, and who controls the machines that increasingly mediate human life. As of 2025, the AI revolution is still in its opening chapter, and nobody can say how it ends. A quarter of the way through the twenty-first century, the only safe prediction is that the century will keep rewriting the rules — and that the shocks are not over.
Further reading in works of reference and scholarship:
- Encyclopaedia Britannica, entries on the September 11 attacks, the Iraq War, and the COVID-19 pandemic
- United Nations, reports on the COVID-19 pandemic and the Paris Agreement (2015)
- Intergovernmental Panel on Climate Change (IPCC), Sixth Assessment Report
- World Bank, Global Economic Prospects and reports on the 2008 financial crisis
- Lawrence Wright, The Looming Tower: Al-Qaeda and the Road to 9/11 (Knopf)
- Adam Tooze, Crashed: How a Decade of Financial Crises Changed the World (Viking)