The Shape of a Human Tide Is Cut by a Document

Granada fell on 2 January 1492 and the Reconquista ended. On 31 March, Ferdinand and Isabella signed the Alhambra Decree: Jews had until 31 July to convert or leave. The negotiator was Isaac Abravanel, royal finance official and leader of the Jewish community; across the table stood the Inquisition, established in 1478.

Abravanel offered a large sum to buy the decree back, and the crown — fresh out of a ten-year war and financially strained — had reason to listen. But the real mechanism sits in the text of the decree itself: what it keeps returning to is not Jews but conversos, the New Christians forcibly baptized in waves since 1391. The Inquisition had concluded they still kept contact with Jewish kin and retained Jewish practice, and that the "source of temptation" therefore had to be removed. This was a quarantine policy aimed at people who had already converted, with the cost paid by those who had not. The numbers remain contested: the traditional figure is 300,000, while Henry Kamen, working from tax rolls, estimates 40,000–80,000 actually left, most choosing baptism instead — the decree manufactured more conversos than it expelled Jews. Those who left went to Salonica, Livorno and later Amsterdam; Jonathan Israel shows that the cross-border credit network of seventeenth-century Sephardic merchants was precisely this dispersal rewired.

The deadlock inside loyalty vetting: once a group is defined as needing to prove its own innocence, any evidence can be read as camouflage, and the process can never close.

From the late seventeenth century the Dutch East India Company (VOC) expanded sugar production around Batavia, recruiting large numbers of migrants from Fujian. When Caribbean output rose in the 1720s and sugar prices collapsed, Javanese mills failed in batches and unemployed Chinese workers accumulated outside the city. Governor-General Adriaan Valckenier (in office 1737–1741) was already in a factional fight with his deputy, van Imhoff.

On 25 July 1740 the VOC council resolved that Chinese without residence permits would be deported to plantations in Ceylon. Once the round-ups began, a story spread outside the walls: those put on ships never reached Ceylon but were thrown overboard. Leonard Blussé's Strange Company (1986) notes the rumour cannot be verified — but it determined what followed. On the night of 8 October armed Chinese gathered and attacked the city; the next day the VOC ordered house-to-house searches for weapons inside the walls, and within hours the search became a massacre that ran for three days, leaving almost none of the roughly ten thousand Chinese inside the city alive. Valckenier was dismissed and jailed the following year and died in prison in 1751; no verdict was ever delivered. Yet the VOC did not expel the Chinese afterwards — it could not do without them. Chinese residents were confined to Glodok outside the walls, and the Kapitan Cina system was reinforced at the same time: the VOC appointed Chinese headmen to collect taxes and farm monopolies, institutionalizing a migrant community as the tax-collecting middle layer — protected from above, extracting from the society below. The structure lasted two centuries.

The middle layer of the platform economy — resellers, outsourced moderators, channel partners: they absorb the friction and the anger, and when something breaks they are the first to be dropped by both sides.

Potato blight reached Ireland in September 1845, where roughly three million people lived almost entirely on potatoes. Prime Minister Robert Peel quietly bought Indian corn to hold prices down and left office in June 1846; the incoming Russell government handed relief to Charles Trevelyan, Assistant Secretary to the Treasury.

The Poor Law Extension Act passed in June 1847 carrying a clause added by the landlord MP William Gregory: anyone holding more than a quarter of an acre was, along with their family, ineligible for any poor relief. The logic reads well — relief should go to the poorest. The effect was to force more than three hundred thousand smallholders into one choice: give up the land in order to eat. Landlords acquired a legal instrument for clearing their estates, and roughly 250,000 people were evicted between 1847 and 1854. Trevelyan meanwhile shifted the cost of relief onto Irish local rates, and the western counties that needed relief most had the thinnest rate base. Between 1845 and 1852 about a million people died and 1.5 million left; mortality on the 1847 crossings was high enough that the quarantine station at Grosse Île in Canada buried five thousand in a single year.

The cliff effect in asset-tested welfare: eligibility requires applicants to first sell the car, the tools and the thin savings — repairing today by dismantling next year.

At the Évian Conference of July 1938, thirty-two states discussed taking in Jewish refugees from Germany and Austria; almost none committed apart from the Dominican Republic, and Nazi propaganda promptly announced that nobody wanted them. After the war every government understood that an institution was needed — and equally did not want open borders. The conference of plenipotentiaries convened in Geneva in July 1951.

The fight was not over whether to protect but over how wide to write the definition. The American delegation pushed narrow and insisted on two gates: the convention would cover only events occurring before 1 January 1951, and a signatory could declare it applicable only to events occurring in Europe. Article 1 A(2) as adopted defines a refugee as someone with a well-founded fear of persecution for reasons of race, religion, nationality, membership of a particular social group, or political opinion — people fleeing war, famine or environmental disaster are outside it, and so is anyone who has not crossed a border. Only the 1967 Protocol removed the two gates; the United States never signed the convention itself. Today more than 120 million people are displaced worldwide, the largest share of them internally — for whom the convention has not a word.

The definitional fight in AI governance: thresholds for "frontier model" or "high-risk system" written narrow are enforceable but miss most of the field; written wide, nobody signs. The same structure, replayed seventy years on.