Strikes in Iran, Harlem Renaissance, and Selling Mechanical Reapers

What is involved in nuclear proliferation?

Nuclear proliferation is the spread and increase of nuclear weapons and technology that has defined international security since the atomic era began in 1945. Due to their catastrophic effects—the ability to knock out entire cities (watch how they work)—nuclear weapons posed an existential threat to the global order and arguably became a deterrent to war between major powers.

The nuclear weapons age began with the United States' Trinity test and the atomic bombings of Japan. The Soviet Union followed by detonating a nuclear bomb in 1949, sparking an intense arms race that peaked with global stockpiles of over 60,000 warheads in the mid-1980s (see chart). Today, nine states possess nuclear weapons, collectively maintaining over 12,000 warheads.

International efforts to curb proliferation, at their height in the 1980s, included the International Atomic Energy Agency, the Nuclear Non-Proliferation Treaty, and decades of US-Russia arms control agreements that reduced stockpiles and provided mutual transparency through on-site inspections and data sharing.

Increasing tensions between Russia and the United States, China's rapid nuclear buildup, and allies' doubts about the reliability of American security commitments have raised the prospect of renewed arms races.

... Read what else we learned about nuclear proliferation here. 

Also, check out ... 

> Some experts argue nuclear war is more likely than commonly believed. (Listen)

> South Africa is the only nation to build nukes and then voluntarily dismantle them all. (Read)

> Everything we learned about the logistics and history of the Manhattan Project. (Explore)

> An interactive timeline detailing the 13 days of the Cuban Missile Crisis. (Explore)

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How did it all begin?

The Harlem Renaissance was an early 20th-century arts movement that took place in the Harlem neighborhood of New York's Manhattan borough (see landmark map), a major destination during the Great Migration of Black people from the American South. Most scholars say that it began in earnest in the mid-1920s and ended with the Great Depression, when high unemployment in Harlem forced many venues to close.

The movement was a groundswell of expression through literature, music, dance, theater, visual art, political activism, and other modes by Black artists that reclaimed Black identity and heritage. Foundational texts by Alain Locke and Langston Hughes in 1925 and 1926, respectively, argued that Black people needed to define their own culture rather than passively accepting the portrayal of Black culture by mainstream media and art.
 

Harlem Renaissance artists like Cab Calloway, Aaron Douglas, Duke Ellington, Claude McKay, Augusta Savage, Jean Toomer, and Zora Neale Hurston (browse list) produced innovative works that influenced American culture for generations and helped inspire artistic and political movements like the Beat Generation, the American Civil Rights movement, and the Black Arts Movement.

... Read our full explainer on the Harlem Renaissance here. (And to be the first to receive brilliant culture dives like this, sign up for our weekly Society and Culture newsletter, sent Saturdays at 8 am ET.)

Also, check out ... 

> Read the first (and only) issue of the magazine started by Langston Hughes, Zora Neale Hurston, and others. (Read)

> Jazz was an integral part of the Harlem Renaissance. (Read)

> Browse a collection of Harlem Renaissance poetry. (Browse)

> Duke Ellington's "Harlem" takes listeners on a stroll through the neighborhood. (Explore)

What happened after the Civil War?

The Reconstruction era, lasting from 1865 to 1877, was the period when the US federal government sought to reunite the nation after the Civil War. Key issues included how to punish Confederates, readmit Southern states, and secure rights for newly freed Black Americans (read Lincoln's original plan).
 

Following Abraham Lincoln's assassination days after the war's end, President Andrew Johnson—a pro-Union, pro-states' rights Southerner—pursued a lenient approach to reconciliation. He pardoned former Confederates, restored their property, and allowed Southern states to govern with little federal oversight. Those states quickly enacted laws restricting the freedoms of formerly enslaved people, while groups such as the Ku Klux Klan targeted Black communities and leaders with violence.
 

In response, Congress defied Johnson's resistance—even impeaching him—and passed the Reconstruction Acts, which imposed military rule in the South and required new state constitutions guaranteeing civil rights and Black male suffrage. This ushered in a brief period of Black political participation in the South.
 

However, following the contested presidential election of 1876, Rutherford B. Hayes withdrew federal troops, effectively ending Reconstruction and allowing Southern Democrats to reestablish a racial hierarchy through Jim Crow laws.
 

... Read our full write-up on the period here.

Also, check out ... 

> How the Freedmen's Bureau was built to help former slaves after the Civil War. (Read)

> Thousands of Black men held local, state, and federal offices during Reconstruction. (Watch) | Listen to their stories. (Listen)

> Southern Black Codes sought to preserve prewar racial labor structures. (Read)
> The Reconstruction amendments to the Constitution aimed to rebuild the nation and secure freedom for former slaves. (Read)

In partnership with Noom

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Best of the Week

We added 374 resources this week to our knowledge collective—share your favorite link or outlet with us to see it featured here next week!

Mapping where food inflation is expected to hit hardest this year. (View)

How the 1830s inventor of the mechanical reaper anticipated modern sales tactics like financing, live demos, data collection, and recurring service. (Read)

The ultrawealthy hold a minimum of $30M in 2026. (Read)

How Netflix built its familiar, three-second sound logo it dubs "Tudum." (Listen)

An updated, innovative online encyclopedia of perfumes. (Interact)

Olive oil, African dates, and Persian peaches: What was the daily diet for a typical ancient Roman? (Read)

Trove of posthumous paintings reveals Jean-Michel Basquiat's technical skill and process. (View)

Check out what makes British Columbia's "Infinite Coast" so special. (Explore)

How streamers mediate our divergent understanding of the Vietnam War. (Read)

A gallery of medical illustrations from NIH. (View)

The tragic story of the doomed Donner Party in search of a shortcut West. (Listen)

A photo essay on the obscure sport of "French ring," where protection dogs compete in feats of obedience and athleticism. (Read)

Historybook: Articles of Confederation are ratified, go into effect in the US (1781); Writer Ralph Ellison born (1914); Harry Belafonte born (1927); The Peace Corps is established (1961); Actress Lupita Nyong'o born (1983); Justin Bieber born (1994).