When King Charles’s mother became the first British monarch to address the United States Congress in 1991, she spoke in the aftermath of the US-led response to Saddam Hussein’s invasion of Kuwait, in which more than 50,000 UK troops participated. Queen Elizabeth II used the occasion to celebrate the role of the transatlantic alliance in upholding the rule of international law: “Some people believe that power grows out of the barrel of a gun,” she told her Capitol Hill audience. “So it can, but history shows that it never grows well nor for very long.”

Different monarch, different times and a very different America. As the king embarks on a four‑day state visit to the United States, a foiled assault by a gunman believed to be targeting members of the Trump administration illustrated the extent to which political violence has become endemic in a deeply polarised country. Globally, Donald Trump’s illegal war in Iran (and prior to that the abduction by US special forces of Venezuela’s president, Nicolás Maduro) underlines that in the view of the present White House, the possessors of military might have the right to set their own rules.

In his own address to Congress this week, marking the 250th anniversary of US independence, the king will doubtless refrain from any direct critique of that presumption. Instead, he will seek to navigate safer territory, recalling an alliance that spanned two world wars and was strengthened through solidarity after the horror of 9/11. Necessarily, this will amount to a regal exercise in damage limitation.

As the White House has turned on Britain, and Sir Keir Starmer in particular, over the UK’s failure to do its bidding in the Middle East, the prime minister’s early hopes of becoming a conciliatory bridge between Mr Trump’s Washington and the European Union now appear naive. The volley of presidential insults and threats delivered via the Truth Social platform has, ironically, allowed Sir Keir to enjoy a vanishingly rare moment of public approval for his relatively robust response. But by pushing ahead with the state visit in such circumstances, the government has given the king what in footballing parlance is known as a “hospital pass”.

For Mr Trump, whose narcissism blinds him to many truths, the king’s trip – the first such state visit since 2007 – will inevitably be treated as a personal tribute as well as a gesture honouring the US on its birthday. Given the lethal havoc that he has unleashed in his second term of office, and the disrespect he has shown to Britain’s elected government, its armed forces and its multicultural modern reality, that sticks in the craw. The unfolding of the Epstein scandal, as the king’s brother is investigated by police and the Trump administration refuses a full release of related files, adds another unsavoury dimension to the visit.

A skilful diplomat, the king will endeavour to make the best of a bad job. But if his mother spoke in Washington at a high point for the “special relationship”, the present monarch arrives at a historic nadir. Saluting the democratic values at the heart of the Declaration of Independence in 1776 may serve an edifying purpose, given a president who treats them with contempt. But once the king is back in Buckingham Palace, a veil should be drawn over the government’s failed charm offensive with a rogue head of state.

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