An extraordinary story—extraordinary from many angles—in the January 8 issue of the Washington Post (Roxanne Roberts, “Palm Beach Used to Be a Nice Town for Billionaires. Then Trump Came Along”) explains how President Trump disrupts the residents of the whole island when he comes to his Mar-a-Lago Club in Palm Beach FL with his heavy security detail. He is not the only contemporary head of state to have a humongous security apparatus, even if his may be the most obtrusive, at least in more or less liberal countries. And the Secret Service is probably not worse under Trump than under other recent presidents.

It is interesting to compare this situation with that of tyrants in ancient Greece. The nature of the beast varied much between the eight and the third century B.C. But many tyrants were adulated by the demos (the mob) or elected to solve what we would today call “national emergencies.” Contrary to kings, they were above the law. They ruled by power, money, and mob support. In her fascinating little book, Greek Tyranny (Oxford University Press, 2009), Sian Lewis explains that Greek tyrants often had no bodyguard. Agathocles, who ruled Syracuse between 317 and 289 BC, “prided himself on not using a bodyguard and cultivated an unassuming attitude in public.” Of Gelon I, who also ruled Syracuse two centuries earlier, Lewis writes that he “summoned the people to an assembly fully armed”—the people were fully armed, not Gelon! Lewis continues by quoting historian Diodorus Siculus:

[Gelon] appeared before them not only unarmed, but without even a tunic, wearing only a cloak… The crowd … were amazed that he had entrusted himself unarmed to anyone who might wish to kill him, so much that they … with one voice hailed him as their benefactor, saviour and king.

Somewhat like today’s heads of state, Roman emperors had their Praetorian Guard—which does not mean they were loathed by the populus romanus, that is, the majority of the people. But was a tyrant like Agathocles or Gelon really more loved than an American president?

Heavy, continuous protection of the U.S. president is relatively recent. The Warren Commission’s report on the assassination of John F. Kennedy contains an appendix on “A Brief History of Presidential Protection.” A few excerpts:

In the early days of the Republic, there was remarkably little concern about the safety of Presidents and few measures were taken to protect them.

For the inauguration [of Abraham Lincoln], the Army took precautions unprecedented up to that time and perhaps more elaborate than any precautions taken since.

It was only after William McKinley was shot [in 1901] that systematic and continuous protection of the President was instituted.

The attack on President Truman led to the enactment in 1951 of legislation that permanently authorized the Secret Service to protect the President.

Besides their interest in creating an aura of God-like power around them, I can think of at least four economic reasons why contemporary rulers, whether democratic or not, need more protection than ancient tyrants.

The first factor lies in the progress of the technology of tyrannicide. In ancient Greece, to kill a tyrant, one had to get very close to him, probably deep within an entourage or crowd of worshippers, and to manually shove a dagger into his chest, risking immediate retribution from the mob. A contemporary handgun can efficiently deliver a powerful bullet 25 to 50 feet away; a rifle, a few hundred feet away. Olof Palme, the Swedish prime minister was killed at close range by an assassin’s revolver in a Stockholm street in 1986 (interestingly, his killer has never been found). In 1963, John Kennedy was killed with a rifle from 180 feet away. Not to speak of bombs, which can be made with readily available materials.

The second factor is the relative wealth of the potential assassins. Nearly everybody owns a car to drive wherever he chooses to ambush his target. Or he can rent one with a credit card. A firearm or bomb materials cost only a small part of a potential assassin’s income.

The third reason is globalization, which combines with technology and the special vulnerability of open societies. A foreign terrorist can fly to an open society and has a reasonable chance to hit an unprotected target. More than other heads of state, an unprotected U.S. president would be vulnerable to global terrorists, who sometimes have reasons to hate America. (Note this is a purely positive statement. I am not criticizing globalization in general; my view is the opposite.)

It’s a fair assumption, though, that heads of state would still be tightly protected even without the fear of foreign assassins. Their heavy protection goes back long before the rise of Islamist terrorists. Something else must be at play.

Note in passing that, at least from the early 20th century,  a factor specific to America is the availability of handguns to ordinary citizens. Yet, only two presidents were assassinated in the 20th century, and only one of them with a handgun (McKinley in 1901). Theodore Roosevelt was shot after he had left office, but the handgun bullet was stopped by his eyeglass case and the folded manuscript of a long speech—which probably illustrates how the technology of today’s ammunition has progressed. (Again, I am not criticizing the Second Amendment; my view is the opposite.)

The fourth factor at play, especially in modern liberal societies, is the high level of diversity. In a relatively homogeneous Greek city-state, the variation of preferences about the performance of a tyrant was limited: most individuals more or less loved the tyrant to the same degree; or they hated him and his days were probably counted. In a diversified society with a wide variation of individual preferences, some will blindly love the ruler while others will passionately hate him. This passion variation is likely to increase with the power of the state as the stakes are higher.

Such diversity has little to do with immigrants, and everything to do with the free or at least open character of our societies. Consider the last presidential election and its aftermath. One-third of the electorate hated Hillary Clinton and voted for Donald Trump. Another third hated Trump and voted Clinton. The last third stayed at home, at work, or at play, and did not vote. This polarized situation has not changed since the election. And, of course, Clinton would have disrupted the residents of the Hamptons as much as Trump now disrupts those of Palm Beach.

This positive explanation (did I forget something?) does not change what I think would be a commendable sentiment for any citizen. There is something obscene in ostentatious and obtrusive security measures for an elected politician. Even if we heed the lessons of public choice economics to the effect that politicians are pursuing their own self-interest, taking risks for the professed common good should be part of the job description.