War has been a catastrophe for Ukraine and a crisis for the globe. The world is a more unstable and fearful place since Russia invaded its neighbor on Feb. 24, 2022.

One year on, thousands of Ukrainian civilians are dead, and countless buildings have been destroyed. Tens of thousands of troops have been killed or seriously wounded on each side. Beyond Ukraine’s borders, the invasion shattered European security, redrew nations’ relations with one another and frayed a tightly woven global economy.

Here are five ways the war has changed the world:

THE RETURN OF EUROPEAN WAR

Three months before the invasion, then-British Prime Minister Boris Johnson scoffed at suggestions that the British army needed more heavy weapons. “The old concepts of fighting big tank battles on European landmass,” he said, “are over.”

Johnson is now urging the U.K. to send more battle tanks to help Ukraine repel Russian forces.

Despite the role played by new technology such as satellites and drones, this 21st-century conflict in many ways resembles one from the 20th. Fighting in eastern Ukraine’s Donbas region is a brutal slog, with mud, trenches and bloody infantry assaults reminiscent of World War I.

Read more: Biden to meet eastern flank NATO leaders amid Russia worries

The conflict has sparked a new arms race that reminds some analysts of the 1930s buildup to World War II. Russia has mobilized hundreds of thousands of conscripts and aims to expand its military from 1 million to 1.5 million troops. The U.S. has ramped up weapons production to replace the stockpiles shipped to Ukraine. France plans to boost military spending by a third by 2030, while Germany has abandoned its longstanding ban on sending weapons to conflict zones and shipped missiles and tanks to Ukraine.

Before the war, many observers assumed that military forces would move toward more advanced technology and cyber warfare and become less reliant on tanks or artillery, said Patrick Bury, senior lecturer in security at the University of Bath.

But in Ukraine, guns and ammunition are the most important weapons.

“It is, for the moment at least, being shown that in Ukraine, conventional warfare — state-on-state — is back,” Bury said.

ALLIANCES TESTED AND TOUGHENED

Russian President Vladimir Putin hoped the invasion would split the West and weaken NATO. Instead, the military alliance has been reinvigorated. A group set up to counter the Soviet Union has a renewed sense of purpose and two new aspiring members in Finland and Sweden, which ditched decades of nonalignment and asked to join NATO as protection against Russia.

The 27-nation European Union has hit Russia with tough sanctions and sent Ukraine billions in support. The war put Brexit squabbles into perspective, thawing diplomatic relations between the bloc and awkward former member Britain.

“The EU is taking sanctions, quite serious sanctions, in the way that it should. The U.S. is back in Europe with a vengeance in a way we never thought it would be again,” said defense analyst Michael Clarke, former head of the Royal United Services Institute think tank.

NATO member states have poured weapons and equipment worth billions of dollars into Ukraine. The alliance has buttressed its eastern flank, and the countries nearest to Ukraine and Russia, including Poland and the Baltic states, have persuaded more hesitant NATO and European Union allies, potentially shifting Europe’s center of power eastwards.

There are some cracks in the unity. Hungarian Prime Minister Viktor Orban, Putin’s closest ally in the EU, has lobbied against sanctions on Moscow, refused to send weapons to Ukraine and held up an aid package from the bloc for Kyiv.

Western unity will come under more and more pressure the longer the conflict grinds on.

“Russia is planning for a long war,” NATO Secretary-General Jens Stoltenberg said at the end of 2022, but the alliance was also ready for the “long haul.”

A NEW IRON CURTAIN

The war has made Russia a pariah in the West. Its oligarchs have been sanctioned and its businesses blacklisted, and international brands including McDonald’s and Ikea have disappeared from the country’s streets.

Yet Moscow is not entirely friendless. Russia has strengthened economic ties with China, though Beijing is keeping its distance from the fighting and so far has not sent weapons. The U.S. has recently expressed concern that may change.

China is closely watching a conflict that may serve as either encouragement or warning to Beijing about any attempt to reclaim self-governing Taiwan by force.

Putin has reinforced military links with international outcasts North Korea and Iran, which supplies armed drones that Russia unleashes on Ukrainian infrastructure. Moscow continues to build influence in Africa and the Middle East with its economic and military clout. Russia’s Wagner mercenary group has grown more powerful in conflicts from the Donbas to the Sahel.

In an echo of the Cold War, the world is divided into two camps, with many countries, including densely populated India, hedging their bets to see who emerges on top.

Tracey German, professor of conflict and security at King’s College London, said the conflict has widened a rift between the “U.S.-led liberal international order” on one side, and angry Russia and emboldened rising superpower China on the other.

A BATTERED AND RESHAPED ECONOMY

The war’s economic impact has been felt from chilly homes in Europe to food markets in Africa.

Before the war, European Union nations imported almost half their natural gas and third of their oil from Russia. The invasion, and sanctions slapped on Russia in response, delivered an energy price shock on a scale not seen since the 1970s.

The war disrupted global trade that was still recovering from the pandemic. Food prices have soared, since Russia and Ukraine are major suppliers of wheat and sunflower oil, and Russia is the world’s top fertilizer producer.

Grain-carrying ships have continued to sail from Ukraine under a fragile U.N.-brokered deal, and prices have come down from record levels. But food remains a geopolitical football. Russia has sought to blame the West for high prices, while Ukraine and its allies accuse Russia of cynically using hunger as a weapon.

The war “has really highlighted the fragility” of an interconnected world, just as the pandemic did, German said, and the full economic impact has yet to be felt.

The war also roiled attempts to fight climate change, driving an upsurge in Europe’s use of heavily polluting coal. Yet Europe’s rush away from Russian oil and gas may speed the transition to renewable energy sources faster than countless warnings about the dangers of global warming. The International Energy Agency says the world will add as much renewable power in the next five years as it did in the last 20.

A NEW AGE OF UNCERTAINTY

The conflict is a stark reminder that individuals have little control over the course of history. No one knows that better than the 8 million Ukrainians who have been forced to flee homes and country for new lives in communities across Europe and beyond.

For millions of people less directly affected, the sudden shattering of Europe’s peace has brought uncertainty and anxiety.

Putin’s veiled threats to use atomic weapons if the conflict escalates revived fears of nuclear war that had lain dormant since the Cold War. Fighting has raged around the Zaporizhzhia nuclear power plant, raising the specter of a new Chernobyl.

But the conflict has also brought reminders that, sometimes, individual human actions make all the difference. Defense analyst Clarke said one such moment occurred a day after the invasion, when Zelenskyy filmed himself outside in Kyiv and vowed not to leave the city.

“That was critical in showing that Kyiv would fight,” Clarke said. “And with that, of course, the United States, Joe Biden fell in behind it. If those two things hadn’t happened — Zelenskyy and then Biden’s decision — the Russians would have won.

“That Zelenskyy moment will go down in history as very, very important.”