When Xi Jinping, China’s president, arrives in the UK late on Monday, he will be embarking upon what promises to be the most important diplomatic visit to Britain in several years. A strenuously lavish welcome is planned; he will stay in Buckingham Palace, ride in a royal carriage, address some 600 MPs in a rare speech to both houses of parliament and be escorted to Manchester by David Cameron, the prime minister. Multibillion pound Chinese investment plans are set to be trumpeted as both sides hail a new “golden era” or “golden decade” in bilateral ties.

The crucial importance of the trip, though, lies beyond the imperial pomp that Mr Xi will be afforded and the deals his entourage may deliver. The visit is set to mark a fundamental recalibration in the UK’s great power relations. By pursuing an uncritical charm offensive toward Beijing in pursuit of commercial gain, London has opened a chasm between its foreign policy imperatives and those of the US, which retains deep suspicions of China over issues such as cyber espionage and territorial disputes in the South China Sea. Washington has already complained over the UK’s “constant accommodation” of China following London’s decision to join the Beijing-led Asian Infrastructure Investment Bank (AIIB) this year. The fervour of Mr Xi’s welcome this week is likely to intensify US concerns, though Washington may reflect that London’s pro-China tilt is in part a consequence of its own judgment that the UK does not reside at the heart of European affairs.

Britain’s shift toward the Middle Kingdom shows no sign of being a mere temporary expedience. Careful cultivation has characterised each step of the UK’s journey back from a diplomatic freeze following Mr Cameron’s decision in 2012 to host the Dalai Lama, the exiled Tibetan spiritual leader who Beijing regards as a separatist. Downing Street has let it be known that Mr Cameron has no plans to meet with the Dalai Lama again, while George Osborne, the chancellor, declined last month while visiting China to criticise the country’s human rights record — winning praise from the state media for his “etiquette”. The personal delivery of the Queen’s invitation to Mr Xi by Prince William earlier this year also helped build confidence. But the biggest boost to Sino-UK relations came when Britain ignored objections from Washington and jumped the queue to join the AIIB, paving the way for other western powers to follow suit.