Sir Mark Thatcher, son of former British prime minister Margaret Thatcher, has just been arrested on charges of conspiring to overthrow the government of Equatorial Guinea. Equatorial where?

“The United States has not posted an ambassador to Equatorial Guinea since 1994, a year after the last one, John E. Bennet, was accused of practicing witchcraft.” – The Washington Post, May 2001.

Equatorial Guinea is one of those rare cases in which the discovery of oil has not made the country’s politics worse. Because that would have been all but impossible. Equatorial Guinea’s government already existed in a state of near-total dysfunction.

The country’s paralyzed bureaucracy, ridden with corruption, fails to provide basic health and sanitation services to most of the population. To such an extent that average life expectancy, in what is now one of Africa’s richer nations, is about 55 years. Worse than Cambodia and Sudan; about on par with Laos.

As colonies go, Equatorial Guinea was fairly well-off as of the 1950s, under Spanish rule. It was an unlikely country, though. A collection of islands, the largest of which, Bioko, is actually off the coast of Cameroon – plus a random patch of West African coastline. All located due south of Nigeria. The first post-independence president, Francisco Macias Nguema, afflicted by madness or ignorance, unleashed a campaign of terror that led to the death or exile of an estimated third of the population. Under his misrule the capacity of the state to do anything – much less maintain infrastructure or provide health care – diminished nearly to nothing.

Macias was overthrown and executed by his nephew, Obiang, in 1979, not before time. This resulted in genuine improvements – education restarted, World Bank advisors invited in. But spectacular corruption continued and Obiang’s rule was far from democratic. Opposition leaders were arrested and tortured, and Obiang won sham elections with 97 percent of the vote.

So what attracted Sir Mark Thatcher, son of Margaret, to involvement with this unfortunate country? That is no mystery. In 1995, oil was discovered. Equatorial Guinea’s economy expanded by a staggering 1500 percent in a few short years. Oil production leapt from next to nothing to 350,000 barrels per day.

At this point Equatorial Guinea’s position became somewhat precarious. The tiny, dysfunctional country’s survival had been predicated on the fact that it was uninteresting. But with oil, this changed. Mercenaries tried to invade in 1997; separatists attempted a rebellion in 1998; then a coup attempt in 2002. Obiang put these down with relentless brutality and the help of some well-armed foreign bodyguards.

But in 2004 an aging group of mercenaries – many of them veterans of Executive Outcomes, the infamous mercenary firm which fought civil wars on behalf of oil-rich regimes in Sierra Leone and Angola – gathered in South Africa for the proverbial “one last job.” This was to depose the government of Equatorial Guinea, in exchange for cash and oil contracts. An opposition leader, Severo Moto, in exile in Madrid, would take power. Obiang would be flown to Spain.

But it all went spectacularly wrong. Most notably the plotters seemed not to understand that the government of South Africa – in the days of apartheid sympathetic to such adventures – now sought stability in Africa. The mercenaries were arrested, variously in Equatorial Guinea, South Africa and Zimbabwe.

And they began to talk. For this credit partly the Equatoguinean government’s use of torture – one of the mercenaries in its custody has already died, in disputed circumstances. South African police arrested Thatcher on suspicion of being one of the plot’s financiers.

An unhealthy attraction to be sure. And one that is not limited to aging mercenaries. In the past, the United States took a strong stand against Equatorial Guinea’s authoritarianism and kleptocracy. In the early 1990s the US ambassador criticized the government’s human rights record. He was formally accused – literally – of practicing witchcraft and told to leave the country. In one of those rare examples of backbone that makes one proud of the Foreign Service, he used his farewell address to name the government’s most notorious torturers.

But all that has changed. The first oil in Equatorial Guinea was discovered by Mobil. Marathon and Amerada Hess, also American companies, are now in the country. Suddenly, the United States has rediscovered a “positive, constructive” relationship with Equatorial Guinea. Though there is little improvement in the human rights situation.

This is surely yet another unhealthy attraction. It is a failure to learn the bitter lessons of the Middle East, where US support for despotic oil-rich regimes in Iran and Saudi Arabia helped create an implacable enemy and Islamic terror, respectively.

At the very least it is a failure to learn the lessons of Nigeria, only a short hop to the north. There, in the Niger Delta, oil-fueled ethnic violence rages with such force it has stopped oil production repeatedly in recent years. Surely these are experiences that America and its oil companies ought to be in no hurry to replicate. As a new source of supply, Equatorial Guinea is attractive. But this blossoming relationship, on current terms, is, in the long run, unlikely to do any of the parties much good.

This article was originally published on Countryrisk.com, before I sold it to Roubini Global Economics.