In February 1945, over lunch in Cairo, the leaders of Great Britain and Saudi Arabia met face to face for the first time. Churchill was just concluding his stewardship of the allied victory in the second world war, while King Abdulaziz, the creator of modern Saudi Arabia, could savour his equally historic unification of the warring tribes of the Arabian peninsula. Often better known in the west as Ibn Saud, the Saudi monarch was the grandfather of the kingdom’s de facto new ruler, Prince Mohammed bin Salman, who arrives in the UK on a diplomatic visit on Wednesday.

Saluting Ibn Saud’s puritanical Wahhabi principles when they met, Churchill gracefully acknowledged that it was the “religion of his majesty to deprive himself of smoking and alcohol”. But he made clear that his own rule of life “prescribes as an absolutely sacred rite of smoking cigars and also the drinking of alcohol before, after, and if need be during all meals and in the intervals between them”. Let us hope that Theresa May is equally forthright in setting out Britain’s cultural differences with the crown prince today, making clear Britain’s belief in liberty of speech, freedom from arbitrary arrest, the independent rule of law, and the sacred principle that political leaders – be they monarchs or prime ministers – are not the masters, but merely servants of the people.

Facebook Twitter Pinterest King Abdulaziz with Churchill in Cairo in 1945. Photograph: Print Collector/Getty Images

These are principles for which the 32-year-old, familiarly known as MbS, has yet to show much enthusiasm. Several dozen intellectuals, religious scholars and journalists have been detained without trial in Saudi Arabia since last September – which is why MbS will meet the Queen safely inside the battlements of Windsor – a shift of venue perhaps devised by the Foreign Office to protect him from exposure to demonstrations by human rights campaigners.

Back in those pre-Israel years, Churchill urged the staunchly anti-Zionist Saudi king to help to ease the general Arab welcome to the Jews in Palestine. Britain had subsidised the Saudi monarchy for 20 years before its discovery of oil, argued the prime minister, so a gesture towards the Jewish homeland was the least Saudi could offer to repay the debt. This was a crude wielding of the British “big stick”, in the opinion of Abdulaziz, when he later reported the discussion to the American minister in Jeddah.

Might May try such tough tactics as she seeks to persuade MbS to list or co-list his £1.5tn flotation of Aramco shares through London next year – or dare to inquire of the crown prince if he has secured his people’s approval for this massive sale of national assets? It does not seem likely. There are few big sticks left in the British armoury these days. So, if the prime minister proves no Churchill, what are the ways in which young Prince Mohammed might mirror his famous grandfather?

MbS has wasted no time deliberating like his predecessors over such issues as the need for women to drive, or the urgency of curbing Islamic extremism and the hated religious police. He has just got on with it, in a whirlwind of decrees and government shake-ups that his energetic grandfather might well admire. Cinemas and entertainment centres will open their doors all over the kingdom in the coming months, and when it comes to business corruption, the young man has wasted no time locking up more than 300 suspects – albeit in Riyadh’s Ritz Carlton Hotel.

Play Video 3:18 Reformer or rogue? Saudi crown prince Mohammed bin Salman – video profile

As a consequence, the young crown prince is immensely popular, with many young Saudis – and with women of all ages. But for all his get-up-and-go decisiveness, Abdulaziz spent many hours every week sitting with his advisers, foreign visitors, tribal leaders and ordinary members of the public, listening to their ideas and grievances.

“We have a popular saying,” declared the king in January 1925, when he occupied the holy city of Mecca. “The people of Mecca know best about Mecca’s mountain passes.” Then he promptly set up a local majlis al-shura – a “sitting place for consultation” – where local people could organise matters such as pilgrim transport and city governance, along the lines of a similar consultative council in Riyadh.

Today there exists such a national body, the consultative assembly of Saudi Arabia, set up by King Fahd in the 1990s, consisting of 150 members, some of them women, all nominated by the king. It is an embryo Saudi parliament, and King Abdullah, the predecessor to MbS’s father, King Salman, made muffled noises about opening a percentage of seats to popular election. That talk has stopped abruptly with the advent of the crown prince, whose fierce and headstrong style both at home and abroad in his dealings with countries such as Qatar, Lebanon and, most tragically of all, Yemen, defies all awareness of popular consultation.

Facebook Twitter Pinterest A lorry with a banner protesting against the visit by Prince Mohammed bin Salman in London on 5 March. Photograph: Matthew Chattle/Barcroft Images

Britain bears its own responsibility for the 13,000 people who have been killed in Yemen since 2015, both as the legacy of its “master planning” of the Middle East a century ago, and through the current supplying of lethal weaponry to the Saudi-backed coalition that is fighting the Iranian-backed Houthi rebels. Away from Yemen, MbS has rowed back strongly from the kingdom’s previous support of Islamic extremism, so perhaps May can find common ground for Britain to try a little regional peace-making.

For his domestic reform programme, the crown prince deserves praise. But at the same time, the brash and abrasive young innovator has not encouraged or permitted any popular debate in Saudi Arabia about the nature of his many changes. He appears to be moving the country from old-time religious extremism to his own “You-must-accept-my-reform” extremism, without any consultation – accompanied by arrests and the disappearance of his critics.

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So, does his programme lack the most important reform of all – democracy? The crown prince is proposing to impose Saudi Arabia’s first modern taxes as part of his economic strategy in the face of stagnant oil prices – a very brave and necessary move. But he seems oblivious to the need for any popular discussion or consent to accompany that. “No taxation without representation” is an inflexible lesson of history that Britain has learned the hard way, and May would be doing her guest a great favour to remind him politely of it.

• Jamal Khashoggi was media adviser to the Saudi ambassador in the UK. Now self-exiled in the US, he writes for the Washington Post. Robert Lacey is the author of The Kingdom – Arabia and the House of Saud