When Prince William’s intended visit to Israel and Palestine was announced, one of my colleagues with a profound knowledge of the Middle East was apoplectic. Scion of a military family, he found it difficult to reconcile the idea of the second in line to the throne visiting Jerusalem, where 91 British soldiers were killed by a terrorist attack on the King David Hotel in 1946.

The realpolitik is that the royals in their diplomatic guise are required to toe the line. The Queen, in a gesture of reconciliation, became the first reigning monarch to visit the Republic of Ireland in 2011. In so doing, she had to put aside lingering family memories of Lord Mountbatten of Burma being blown up by the IRA in 1979.

As difficult as memories of the King David may be, cruelty and violence have never been a bar to royal activity. In the Arab Spring, citizens were mown down in Bahrain but its leader recently took tea with the Queen at Windsor. There have been brutalities by Saudi Arabia in Yemen as it seeks to neutralise radical Shia-backed Houthi rebels from the north and terrible civilian casualties as a result of bombings by British-supplied arms to Saudi Arabia, though there is no escaping the fact the Houthi are allied to other radical groups across the Middle East and are violently anti-Israel in rhetoric and symbols.

We live in a post-colonial age. In this context, the royal family is no longer the ultimate symbol of British military power, although that lingers at ceremonial occasions. Instead, it has become a tool of diplomacy. In the post-referendum age, reaching out to trading partners is key.

There was no mistaking the purpose of the red carpet for Saudi Arabian Crown Prince Mohammed bin Salman’s UK visit. As he embarks on a plan of economic and social modernisation, Britain is keen to help the Saudis to spend and invest their money. Theresa May even has a special envoy to the prince in the shape of veteran investment banker Ken Cost, seeking to persuade the Saudis to swallow reservations about transparency and bring the $2trillion float of the Saudi oil company to the London market.

More immediately, Salman’s visit secured a memorandum of understanding on the next purchase by Saudi Arabia of 48 Eurofighter Typhoon jets assembled by British Aerospace.

Nothing so dramatic is on the cards with Israel. But attendees at the recent Israel Britain Business dinner could have been mistaken about the underlying messages. Israel’s Ambassador to the Court of St James Mark Regev extolled the trading relationship, noting that commerce between the two countries rose 25pc in 2017.

Among the FTSE100 companies, relations with Israel have never been better, irrespective of boycott activities. A growing number of UK firms look towards Israel for better cyber security. Even BAE Systems, Britain’s leading defence company, now has R&D facilities inside Israel. The spiritual home of the gaming industries and the City’s spread betting companies also is in Israel.

Previous royal visits to Israel such as Prince Philip’s to Yad Vashem to honour his mother and the Prince of Wales’ attendance at Shimon Peres’ funeral have been personal or specific.

Prince William’s is different. It recognises an important commercial relationship.

The world is turning.