We owe this knowledge to that indispensable journalistic resource, the flight-tracking websites. They revealed that the private plane Mr Netanyahu usually charters for secret visits abroad departed from Tel Aviv on Sunday and flew to Neom in Saudi Arabia, taking off for the return flight three and a half hours later.

Once upon a time this would have been headline news around the world. "US superpower and oil-rich Saudi Arabia get together with embattled Israeli leader to carve up the Middle East", or something along those lines. Whereas today this "summit", if you can call it that, barely gets noticed.

Mr Netanyahu is indeed embattled, but it's corruption charges he's fighting, not a foreign enemy. Mr Pompeo is a soon-to-be-unemployed politician polishing up his CV for a senatorial nomination in 2022 or the Republican presidential nomination in 2024. Prince Mohammed bin Salman is still effectively the dictator of Saudi Arabia, but that no longer cuts much ice in the rest of the world. The meeting was meaningless.

Some of this collapse in relevance is temporary. Mr Netanyahu will eventually go to jail or retire, but Israel will still be the dwarf superpower that bestrides the Middle East militarily.

Mr Pompeo and his employer will soon be out of office, and the United States will recover some of its former position as a "world leader", at least for a while.

But Saudi Arabia will never be back as a mover and shaker. The decline is permanent, because "oil-rich" is a phrase destined to become as obsolete as "carbon copy". The oil revenue of the Arab producers has fallen by more than two-thirds, from US$1 trillion (30.3 trillion baht) in 2012 to only $300 billion this year, and it's never coming back up. The decline so far has been driven mostly by a steep fall in oil prices -- demand rose steadily but oil production persistently rose faster -- but now an absolute collapse in demand looms as well.

As the climate emergency deepens, motor vehicles (which account for half of all oil use globally) are switching to electricity instead. The UK and France are now committed to end all sales of new cars with internal combustion engines by 2030, which means in practice that nobody there will buy a new petroleum-fuelled car after 2025. Many other countries are debating similar measures.

So what happens to a country like Saudi Arabia, where four-fifths of the government budget comes from oil revenues? Budget-cuts are already happening, of course, but revenues will continue to fall. Moreover, the population in almost all the oil-producing Gulf states is still growing fast.

The extraordinary stability of these states -- not a single change of regime in the six "oil-rich" monarchies of the Arabian peninsula in the past 50 years -- has been based entirely on the ability of the traditional rulers to buy the acquiescence of their subjects. Once the wealth goes, so does the stability.

The Arabian peninsula has been briefly a major centre of power only twice in world history: once in 632-661 CE, after which the capital of the early Islamic empire moved to Damascus, and once from 1973 to the present -- but not for much longer.

Even the unity of Saudi Arabia itself, which was imposed by force less than a century ago, may not survive the transition. The dominant power centres of the post-oil Middle East will be exactly where they were for most of the past thousand years: Turkey, Egypt and Iran. And at no time in the last thousand years have any two of those three powers been able to cooperate for long.

They do have some things in common: Islam (although in two different and generally hostile versions), relatively modern, semi-industrialised economies, and around 100 million people each. But they are divided by language (Turkish, Arabic and Farsi have nothing in common except loan-words), distance (the capitals are more than 2,000 kilometres apart), and by history and politics. Egypt occasionally got conquered by one of the other two, but that doesn't count as collaboration. So it might be argued that the "Middle East" itself is about to disappear as a meaningful concept. No great loss, really.