Perhaps Trump is experiencing Putin derangement syndrome, in which a victim believes Russia’s president is a great guy

Why has Trump stayed unusually quiet on US sanctions against Russia?

Donald Trump has brazenly tweeted his private thoughts on a wide range of subjects in recent days, from the incorrigible wickedness of the Iranian regime to the mental acuity of the basketball superstar, LeBron James.

But when the US state department unveiled sweeping new sanctions against Russia over the Skripal affair, the president’s Twitter account fell eerily silent.

What possible explanation could there be for this initial onset of bashfulness? Maybe Trump, enjoying a working vacation at his golf club in New Jersey, was busy swinging iron.

US still under attack from 'pervasive campaign' by Russia, officials warn Read more

Perhaps he ignores anything the state department says on principle. Or perhaps the president is experiencing a fresh bout of Putin derangement syndrome – the flip side of the better-known, anxiety-inducing condition, Trump derangement syndrome.

Sarah Sanders, the White House press secretary, has defined Trump derangement syndrome as a pathologically negative, knee-jerk reaction among Democrats and “liberals” to anything the president does or says. TDS was a “major epidemic”, she said last week.

Putin derangement syndrome (PDS) is rarer. In sum, the victim believes Russia’s president is a great guy and won’t hear a word said against him.

Trump has been exhibiting PDS symptoms for some time. He flatly rejected the unanimous opinion of US intelligence chiefs that the Kremlin meddled in the 2016 presidential election and is poised to do so again in November’s mid-terms. He repeatedly describes the FBI’s Russia inquiry as a witch-hunt.

By all accounts, Trump gave Putin a free ride at last month’s Helsinki summit. He apparently let him off the hook over waging war in Ukraine and Syria, destabilising eastern Europe, subverting western democracies and – on last March’s chemical weapons attack in Salisbury – the genesis of the new sanctions.

“Apparently” is a necessary word in this context, because – extraordinarily – there is no public record of what was discussed in Finland. Even Dan Coats, Trump’s director of national intelligence, says he was kept in the dark.

PDS leads the sufferer to emulate Putin, for instance by keeping everything secret.

So when the Republican senator, Rand Paul, said this week that he had carried a personal letter from Trump to his Kremlin chum, speculation over its contents was intense.

Was Trump secretly giving Putin the heads-up on the new sanctions? Perhaps his letter was reassurance that this hostile move, mandatory under US law once credible evidence has been uncovered, did not reflect his own view – even that he would work around it.

The White House later said the missive was merely a “letter of introduction” and was unclear that Paul even secured a meeting with the Russian leader.

Yet the given the lack of official transparency and Trump’s inexplicably indulgent attitude to Russia’s many-fronted malign activity, such speculation was not wholly deranged.

Few Americans would oppose better relations with Moscow, Trump’s stated objective – if that could be achieved without compromising western security and values.

The problem is, most believe Putin has done nothing to merit detente – and may be exploiting Trump’s naivety or other unknown, more sinister vulnerabilities.

The president appears isolated within his own administration and across Washington. John Bolton, his hawkish national security adviser, Jim Mattis at the Pentagon, a majority in Congress, and the justice department, which recently indicted 12 Russians on hacking charges, all view Putin’s Russia as a hostile predator that should not be appeased.

Trump’s unexplained, initial silence over sanctions, coupled with 19 months of playing patsy, have intensified what may be the biggest question in US politics – what has Putin got on Trump?

James Clapper, a former intelligence chief who believes Russia “turned” the 2016 election, put into words what many Americans must be thinking. “I have been trying to give the president the benefit of the doubt,” Clapper said last month. “But more and more … I really do wonder if the Russians have something on him.”