The war in Ukraine has now lasted 1,568 days — as long as World War I. Here’s what the past tells us about today’s battlefields.

At the start of 2026, Russia’s war in Ukraine surpassed World War II in length. As of June 10, the war in Ukraine has lasted as long as World War I — 1,568 days. Of course, a regional war of the 21st century has little in common with a global conflict of the 20th. But is there anything to be gained from comparing them? And what lessons might the participants in today’s war draw from World War I? Meduza looks back at why the deadliest conflict of a century ago lasted so long, what it cost the countries involved, and what parallels can be drawn with the war of attrition between Russian and Ukrainian forces.

Why did World War I last so long? And what does it have in common with the war in Ukraine?

The nations that entered World War I drew on the experience of earlier great-power conflicts — the Franco-Prussian War of 1870–1871 and the Russo-Japanese War of 1904–1905. Both were relatively short, decided through troop movements and a series of major engagements. In August 1914, most leaders of the Entente and the Central Powers expected the new war to follow the same script: rapid mobilization, decisive offensives, a crushed enemy, and a negotiated peace.

Within months, it became clear the conflict was something else entirely. What had begun as a confrontation of armies became a clash of industrial societies. The outcome depended less and less on battlefield performance alone and more and more on each economy’s capacity to produce weapons, keep transport running, supply troops, and sustain the continuous mobilization of millions of people.

The nature of the fighting shifted as the war progressed. The opening months were mobile: armies moved quickly, launched major offensives, tried to encircle the enemy, and sought decisive engagements. On the Eastern Front and in the war against the Ottoman Empire, front lines could shift by hundreds of kilometers. Even on the Western Front, both sides initially hoped for a quick finish. Those hopes collapsed on both sides: Germany could not crush France and Russia, and the Entente could not destroy the Central Powers.

The war gradually shifted into a positional phase, most pronounced in the west. Trenches, artillery, machine guns, barbed wire, and fortified defensive positions made offensive action extraordinarily difficult. Even enormous losses no longer guaranteed meaningful advances. The battles of Verdun, the Somme, and other sectors of the Western Front exposed the same underlying problem: armies could inflict devastating losses on each other, but a decisive breakthrough never materialized.

Over time, both sides adapted. Assault groups of infantry and engineers developed infiltration techniques to reach and storm enemy trenches. The Entente refined the tactic of breaking through with tank units. Both sides used aviation extensively for reconnaissance and bombing.

None of it was enough to break the positional deadlock entirely. The problem, as it would be more than a century later on the front lines in Ukraine, was the impossibility of rapidly overcoming a deeply echeloned enemy defense and destroying it through maneuver. Behind the first line that assault troops breached after an artillery preparation lay a second. That second line was supported by the enemy’s artillery firing from deep within its defensive positions, while the attacking side’s own guns could no longer assist the advance — they lacked the range.

The slow pace of advance gave the enemy time to move reserves to the point of the initial breakthrough, and offensives invariably stalled. With resources roughly equal on both sides, neither could shift the Western Front even a few dozen kilometers — and that remained true for years, right up to 1918.

As the war dragged on, what it took to win it changed as well. Early on, what mattered most were the plans of the general staffs, the speed of mobilization, and the quality of command. As time passed, other factors became decisive: how many shells a country could produce and how much coal it could mine, how well its transport network functioned, whether there was enough food, whether the state could borrow and keep industry from crisis. Governments began tightening control over their economies, expanding mobilization, regulating production, and intervening in economic life to a degree unprecedented in history.

The state of society became no less important. As the war dragged on and casualties mounted, governments were constantly forced to seek popular support, justify the need for further sacrifice, and hold their countries back from internal collapse. Combat on an unprecedented scale demanded the participation of virtually the entire society — not just the army — for the first time. Mobilization relied on both coercion and propaganda, and the combination gave governments the ability to keep fighting despite human losses, retreats, and economic hardship. Even so, war fatigue accumulated. By 1917, anti-war mutinies were occurring not only in Russia but also in France — following the failed offensive of April 1917 (the “Nivelle Offensive”).

Another reason the war dragged on was that a compromise peace had become increasingly impossible. After millions of deaths and enormous expenditure, no government was willing to stop fighting without a clear victory. Each side expected the other to crack first — under the weight of economic, political, or military strain.

That, in the end, is what happened in the war’s final six months — though not in the way the commanders of either bloc had imagined. Neither side had managed to devise a tactic for rapidly breaking through the full depth of the enemy’s defenses and transitioning to mobile warfare. In the final phase, the balance of forces shifted quickly for other reasons, and that ultimately led to the destruction of Germany and its allies.

Germany initially gained the advantage. After Russia and Romania left the war, Berlin transferred large forces to the Western Front for a decisive offensive. In the spring of 1918, Germany managed — relatively slowly — to push the front line to the Marne River near Paris through assault operations combined with the maneuvering of reserves. But by that point the balance of forces had shifted in the Entente’s favor: American divisions were beginning to arrive on the Western Front — nearly two million men in total by the summer of 1918 — along with British, Canadian, Australian, and New Zealand troops freed up from the Turkish theater.

The Entente offensive that began that summer — the so-called Hundred Days Offensive — destroyed the army of the German Empire. When the armistice was signed, on terms extremely unfavorable to Berlin, Germany had still not relinquished some of the territory it had seized in France and Belgium at the start of the war. Entente armies had never set foot on German soil itself. That fact — together with the revolution that had broken out in Germany by the time the armistice was concluded — later gave Nazi ideologues the opening to claim that the empire’s cause had been lost not through outright military defeat but through betrayal.

In reality, the army had been effectively destroyed, even though the other side had invented no new technology for breaking through defenses and had simply made skillful use of its numerical advantage. The genuine military innovations that combined all the technologies developed during World War I into a single mechanism for breaching defenses, waging mobile warfare, and rapidly destroying even an adversary with comparable resources were introduced by the German Wehrmacht in the late 1930s.

How did World War I end for the countries involved?

Formally, the Entente coalition won. Its core consisted of Great Britain, France, and the Russian Empire — de facto until the Treaty of Brest-Litovsk in March 1918. Italy joined in 1915, Romania in 1916, and the United States in 1917. Serbia, Japan, Belgium, Montenegro, Greece, Portugal, and a number of other states also fought on the Entente’s side.

Opposing them were the Central Powers — Germany, Austria-Hungary, the Ottoman Empire, and Bulgaria — which formally suffered defeat. But the consequences of the war proved far more complex than a simple division into winners and losers.

Germany capitulated, though it had long maintained a strong army and the capacity to resist. By 1918, its economy had been exhausted by the British naval blockade, its population was suffering from food shortages, and its resources for continuing the war were running out. Its allies — Austria-Hungary and the Ottoman Empire — ceased to exist entirely, breaking apart after the war into numerous nation-states.

France and Great Britain emerged among the victors, but victory came at an enormous cost. France lost a large part of its male population and was left with devastated industrial regions in the north and massive debts. Britain kept its empire but emerged financially weakened and dependent on American credit.

Russia was among the biggest losers. Despite having fought on the side of the eventual victors, the country exited the war through revolution, civil war, economic collapse, and the disintegration of the empire.

The United States was the chief relative winner. It entered the war late, avoided destruction on its own territory, sharply expanded its industry, became the largest creditor of the European nations, and significantly strengthened its position in the global economy.

The war ended not only with the military defeat of the Central Powers but with a serious shift in the global balance of power. The center of economic gravity began moving from Europe across the Atlantic.

World War I therefore concluded not simply with the victory of one coalition over another. It concluded with the exhaustion of the European powers, the destruction of several empires, and the emergence of a new international order — one in which economic resilience and the capacity to wage a prolonged war mattered more than swift military victories.