Russia insists it had nothing to do with what it has described as the “pulp fiction” scandal swirling around Donald Trump. But for Vladimir Putin, the dossier affair, following allegations of a compromised presidential election, has the effect, deliberately planned or not, of advancing Moscow’s long-held aim of weakening the US, paralysing its political decision-making process, and avenging Russia’s humiliation at the close of the cold war.

It may be that Putin is entirely innocent, as the Russian president’s spokesmen claim. Or the opposite may be the case. In a sense it does not matter. The damage has been done, and for the Kremlin, it’s a no-lose. The unprecedented confusion and disarray in the US is what old KGB agents like Putin could only dream of.

Putin famously decried the collapse of the Soviet Union, which the US played a leading role in bringing about, as “the greatest geopolitical catastrophe of the [20th] century”. A quarter of a century later, having exhibited the calculated patience of Karla, John le Carré’s fictional Russian spymaster, Putin can savour his revenge – at arm’s length.

Whoever is responsible, doubts have been sown about the independence, trustworthiness, and political legitimacy of the US president-elect. American commentators even suggest Trump may be a Russian “asset”. That carries echoes of another story, Richard Condon’s The Manchurian Candidate, about political brainwashing at the centre of power.

The barrage of claims and counter-claims has fed the suspicions of a large number of Americans that Trump did not win fairly last November. Unease is compounded by an own goal in the electoral process – Trump’s victory in the electoral college despite attracting 3m fewer votes than Hillary Clinton.

The Obama administration itself believes foreign agents, acting for Moscow, worked to influence the election on Trump’s behalf. All the US intelligence agencies agree. That finding has provoked a bitter public rift between Trump, the CIA and the National Security Agency, Washington’s first line of defence and the Russian intelligence agencies’ principal foes.

Since the sources who spoke to Christopher Steele, the former MI6 officer named as author of the dossier, are unidentified, it is impossible to know whether the information he reported concerning Trump’s alleged behaviour in Russia is accurate, or was fabricated by agents of the FSB (the successor agency to the KGB).

Suggestions that the Russians have sufficient compromising information to blackmail Trump, and that Russian agents and hackers fed helpful intelligence to his campaign staff, are similarly alarming. Thus, true or not, some of the mud is certain to stick – the quintessential aim of any KGB-style destabilisation conspiracy designed to destroy confidence and sow confusion.

With Trump yet to be installed in office, the ramifications of this continuing uproar are endless. There will be no honeymoon for him. The current congressional and media frenzy is likely to intensify rather than subside once Trump sits in the Oval Office.

There is already talk of impeachment and a Watergate-sized crisis. Trump is seriously damaged, although his press conference performance on Wednesday suggests he does not realise it.

Many in the US and abroad will view him in one of three ways: dupe, dope, or stooge. Trump’s attempts to enact a policy agenda, domestic or foreign, are likely to be severely undermined by chronic political weakness. This is especially true of anything touching Russia.

If Trump attempts a “reset”, as many expect, he risks being seen as kowtowing to his Moscow handlers. If he tries to strong-arm Nato members, as he promised in the campaign, his motives will be questioned. If, alternatively, he gets tough with Russia over Ukraine, for example, it could be seen by US allies as a dangerous reaction to the scandals rather than a responsible policy shift.

Meanwhile, in anxious eastern and central Europe and the Middle East, fear of Russia will be mixed with new respect. Lavrentiy Beria, Stalin’s legendary chief of state security and head of the NKVD, forerunner of the KGB, would be impressed. The American “target” has been destabilised, its democratic system of governance discredited before the world, and its new leader compromised before he takes power. Time will tell whether Putin has overplayed his hand. Right now, he must be laughing fit to burst – in a plausibly deniable way.