Silicon Valley royalty received a visit from the real thing in April. Google co-founder Sergey Brin and venture capitalist Peter Thiel were among those to meet Crown Prince Mohammed bin Salman of Saudi Arabia during his US tour.

The budding relationship between the two kingdoms was on display again this week. The Financial Times revealed that Saudi Arabia’s sovereign wealth fund had spent about $2bn to acquire almost 5 per cent of Tesla’s shares.

The mutual attraction is obvious. Prince Mohammed has an ambitious agenda to transform his oil economy into an investing and technology powerhouse. For their part, tech companies, especially those burning cash at a rapacious rate, appreciate patient, deep-pocketed investors.

Yet the Saudi tech splurge is far more than meets the eye, while the glaring contradictions and obvious potential for disaster are swept under the carpet.

First, the sprawl. Japan’s SoftBank rightly drew a lot of attention for the size and volume of investments in technology, but remember that almost half of its $100bn Vision Fund is Saudi money. That means that companies as diverse as Slack, the corporate messaging app, and SoFi, the online lender, have Riyadh to thank, in part, for their surging valuations. WeWork, the optimistically-valued shared office provider, received another $1bn this week — so widely is the Saudi/SoftBank fund sprayed around that the news barely registered.

For some prominent companies, it goes further. Almost a fifth of the money raised by Magic Leap, the leading consumer virtual reality company, comes from a $400m direct investment from the Saudi Public Investment Fund. At Uber, the PIF acquired a 5 per cent stake in 2016 before SoftBank bought a 17 per cent stake for $9bn at the end of last year. That adds up to enough financial clout for real influence and, indeed, the PIF’s Yasir Al Rumayyan sits on the ride-hailing company’s board.

For all the crown prince’s vaunted liberalising agenda, he still leads a repressive regime

Those are just the ones we know about. The Tesla revelation shows that the Saudis are prepared to invest quietly in sizeable amounts that stay just below the disclosure threshold of 5 per cent. No other foreign government is close to building such a position in US tech.

And US tech companies should not need reminding that this government’s attitudes are as distant from their own stated values as it is possible to imagine. When Uber gobbled up the first investment from the PIF, women were still barred from driving in the kingdom. Only months ago, Saudi businessmen were locked up in Riyadh’s Ritz-Carlton.

For all the crown prince’s vaunted liberalising agenda, he still leads a repressive regime waging a brutal war abroad and beheading people at home. Given this, the embrace of investment by Silicon Valley’s liberal elite might be their biggest act of hypocrisy yet.

No such qualms are expected from the Trump administration. But these are sensitive industries — SoftBank has stakes in companies such as Nvidia, the leading chip company for artificial intelligence and virtual reality.

And stability is not guaranteed on either side. The Trump administration likes to blow hot and cold, even with allies; it has also made extensive use of its powers to block foreign investments, especially from China.

From the Saudi side, it was striking this week that officials from the kingdom — annoyed by the Canadian foreign minister voicing support for jailed Saudi human rights activists — ordered their overseas asset managers to sell their Canadian equities, bonds and cash holdings, “no matter the cost”. How soon could they tire of a tech sector, which is slow to reciprocate with the hoped-for inward investment in Saudi Arabia. Whether this spending spree ends in boom, bust or fire sale, it will be something to behold.