Loading the record, about a megabyte of sourced events…
escalatory
de-escalatory
mixed
contextual
link between actors
· size = impact 1 to 5
1900191419391945199020112026
A world war can begin gradually and get its start date afterward. This page does not declare one. It hands you the record and the marker.
Keys: space plays, R reels, ← → jump, Esc stops. Open this again with the Guide button.
A world war can begin gradually and get its start date afterward. Nobody on 18 September 1931 knew they were in one; some historians now say they were. This page does not declare a third world war. It puts every sourced event since 1900 on one globe, lets you narrow the window to a day, a month, or a year, and lets you play the record forward. Date it from wherever you like and see what that dating makes you include.
What made the two world wars different was not their geography but the share of a society they consumed. So the record here carries a mobilization layer: conscription introduced or extended, industry placed under state direction, rationing, war finance, reservist call-ups, and military spending as a share of output. Filter to the indicator called Mobilization and war economy and play the record from 1936 or from 2022 to watch the pattern.
The benchmark is 1944, when the United States put roughly thirty-seven percent of output into the war. Russia in 2024 was at about seven percent, Ukraine at a third, most of NATO between two and four, with a pledge of five by 2035. Peacetime conscription and defense exempted from fiscal rules are the signals that come before the numbers move.
Wars are fought over things, and the things run out on a schedule. The record also carries a stress layer: population milestones and the movements of people, harvests and food prices, droughts, floods and record years, the rivers two countries share, oil found, embargoed, peaked and weaponized, and the minerals that a modern army cannot be built without. Filter to Population and migration, Food security and climate stress, Water and land, or Energy and maritime chokepoints and play a decade to see the pressure build before the fighting does.
Political science separates the things states fight over, such as territory, security, resources and identity, from the mechanisms that turn a dispute into violence. The starting point is a puzzle: war destroys what both sides want, so a settlement both prefer to fighting should nearly always exist. The mechanisms below are the reasons states fail to find it, accept it, or keep it. Each is tagged with the level it lives at: the leader, the state, or the system.
The test that fits the label is one question: are at least two major powers shooting at each other directly, in more than one theater? On the record here the present reads as linked wars, not a general one. The broadest alternative, which dates a single global war from the early 2010s, also swallows most of the Cold War, and a label that cannot tell those apart is not doing work.
The United States is at war with Iran. It is not in a world war on the conventional meaning, and there is no accepted list of requirements that can be declared met. The conflicts are more connected than at any point since 1945, and they are colliding without converging: the participants still want different things. What would change this reading is sustained direct combat between major powers spreading across linked theaters, with alliances pulling in more of them. That could justify the label before any nuclear use or any announcement, and a later historian might then date the war from a regional fight that had already been running for years.
Every event on the globe links to the source it was taken from and says whether that link was re-opened for this page. The 2026 indicator rows come from a sourced ledger of 67 items as of 8 September 2026; the earlier record is curated from reference articles and is being checked entry by entry.
Base map: Natural Earth via world-atlas, public domain. Code: github.com/craigm26/date-the-war. Built by Craig Merry, pairing with Claude Code.