“The Bridge on the Drina” won Ivo Andric the 1961 Nobel literature prize. I read it that year and just reread it 60 years later. Back then, it piqued my interest in Yugoslavia, where I studied in 1963–64. Now I see that Andric was writing about more than Bosnia, where he was born and raised.

Bosnia taught him about the stubborn parochialism of cultures, how they are inherited and stay apart and hostile. Andric sees no permanent cure. Normal times and firm governance may suppress nasty cultural differences, but resentments, many religious, simmer perpetually under the surface. Sound familiar?

Andric (1892–1975), a retired Yugoslav diplomat, showed how people dislike change, especially people whose high status seems normal and natural, the only way to ensure social stability. Earlier, when Bosnia was under the Turks, Bosnian Muslims held sway. Serbs (Orthodox Christians) paid a “blood tax” of boys, who were taken to Istanbul to be raised as Muslims and serve the Sultan.

One such boy remembered his weeping mother, who could not follow him across the Drina River. He became Grand Vizier and in 1566 ordered a large, beautiful bridge built at that very spot. The local people, enslaved to build it, soon make it the pride and social center of the town of Višegrad, near Bosnia’s border with Serbia. I rafted under it in 1964.

The Ottomans, weakened by corruption and refusal to modernize, were pushed out of Bosnia in 1878 by the rational, modern Austrians. They introduced hygiene, railroads, electricity and taxes, but Muslim Bosniaks disliked losing their status. Local Serbs, stirred by Serbian nationalism, resented Austria’s annexation of Bosnia in 1908, setting the stage for the 1914 Sarajevo assasination that triggered World War I. The Austrians immediately blew up the bridge (since repaired).

Andric’s novel — more a four-century panorama — shows Muslims and Serbs alike puzzled and disdainful of innovation. Why must things change? Why do we have to build a bridge? The old ferry suffices. Why do the Austrians have to modernize everything, even numbering houses? Austrian control freaks just bring inflation and higher taxes. Fixated on complaining, townspeople barely notice material improvements.

I understand the grumbling of these long-gone folk: Too much change! What is wrong with a telephone that just makes phone calls? Why do I need 30 different passwords, each of which has to be changed every three months? What’s an “app” and why do I need them? Why have we become so dependent on computers that cyber attacks could shut down the country?

Even worse are the parallels between the hatreds of old (and current) Bosnia and ours of today. Didn’t our Civil War settle things? (No.) How did we divide into two hostile tribes? Must all news and claims be doubted? Can we know anything for sure? Result: We withdraw into our post-truth private spheres.

The Point: Wow, does culture persist! Once learned, often over generations, views and behavior don’t change much, if at all. Can you rationally persuade Trump supporters, vaccine refusers and climate-change deniers to abandon their convictions? Don’t count on education to increase tolerance.

What can be done? Bosnia gives some clues. When dominated by a strong authority — Turks, Austrians or Tito’s Communists — tolerance can be enforced. All three, with some brutality, kept subjects obedient if unfree and resentful. As regimes weakened, however, tolerance collapsed into ethno-religious hostility.

In 1964, one Sarajevan told me that Bosnia’s three religions still begrudged each other. During Ramadan, Islam’s month of daytime fasting, Muslim students would say they just weren’t hungry. Catholic Croats put on Austrian airs. Serbo-Croatian was one language, not the current hyped differentiation into Serbian, Croatian, Bosnian and Montenegrin.

Omnipresent security police, the UDBA, cowed everyone. Tito did not build lastingly. He imprisoned truth-speaking comrades (Milovan Djilas) and supposed that hyper federalism solved the nationalities question and “worker self-managed” socialism solved the economic question. They didn’t. New, experimental constitutions came every decade; none worked. (One tried a five-chamber legislature.)

Yugoslavia showcased deceptive calm. While Tito (1892–

1980) lived, there was peace and order. One Belgrade student disliked the Communists but praised Tito: “He’s the only one keeping the dogs on a leash.” Painfully true. After Tito, Yugoslavia dissolved in genocidal wars.

The lesson: When national authority is reasonably strong, we restrain ourselves, curb verbal abuse and abjure violence. Heck, even Reagan was not so bad. Trump, who swears the election was fraudulent, however, widens our latent splits, undermines legitimacy and weakens authority.

This threatens not only democracy but America’s political capacity to fix problems. Our recent increases in gunplay, overdoses, tax avoidance, unattended infrastructure, income inequality and incivility are symptoms of a paralyzed, dysfunctional polity.