Jerusalem

Jerusalem exists because the Gihon Spring exists—a single intermittent water source gushing from limestone on the Ophel ridge, enough to sustain perhaps 2,500 people. Every expansion beyond that original carrying capacity required increasingly ambitious water engineering: Hezekiah's Tunnel (701 BCE) and eventually four Roman-era aqueducts to serve pilgrims flooding a city built on faith rather than trade. The Egyptian execration texts mention 'Rusalimum' around 2000 BCE. King David captured it from the Jebusites around 1000 BCE—a founder effect that fixed the city's identity as the Israelite capital and triggered an information cascade across three civilizations.

Think of Jerusalem as a coral reef of sacred architecture. Solomon's Temple (c. 957 BCE) laid the first polyp; its destruction by Babylon in 586 BCE, its rebuilding, Rome's destruction in 70 CE, the Dome of the Rock (691 CE), and the Crusader conquest of 1099 each layered new sacred construction on the foundations of the old—exactly as coral polyps build on dead predecessors. Judaism, Christianity, and Islam all anchor their claims to the same bedrock, creating overlapping path dependencies with different constituencies. Ottoman Sultan Suleiman rebuilt the walls that stand today in the 1530s. The 1947 UN Partition Plan proposed Jerusalem as a corpus separatum—an internationally administered zone. Instead, the 1948 war produced a phase transition: the city split along the Green Line, with Jordan holding the Old City for nineteen years until Israel captured East Jerusalem in 1967, expanding the municipal boundaries from 6 to 70 square kilometers.

The contested status shapes everything economic for this city of nearly one million people. Most embassies remain in Tel Aviv, depriving Jerusalem of diplomatic-sector activity. The economy runs on government employment (34% of the workforce), pilgrimage tourism (91 hotels, though arrivals collapse during conflict), and a growing tech corridor anchored by Hebrew University. Mobileye, founded by Hebrew University professor Amnon Shashua, sold to Intel for $15.3 billion in 2017. Shashua has founded six AI companies from Jerusalem, yet the city loses thousands of young secular professionals to Tel Aviv annually. The ultra-Orthodox community, comprising roughly a quarter of Jerusalem's residents, has a male workforce participation rate of only 53%. Nearly 40% of Jerusalem families live below the poverty line.

Like an ancient olive tree regrowing from its roots after each cutting, Jerusalem regenerates from the same sacred substrate. It is a temple economy in the oldest sense—a city whose sacred capital permanently exceeds its economic capital. The tech corridor may eventually rebalance the equation, but three millennia of punctuated equilibrium—long stasis shattered by conquest, then regrowth along the same sacred fault lines—suggest that faith, not commerce, will continue to define this city's metabolism.