A Russian spy and his daughter have been poisoned on British soil and the clamour is now growing, in politics and the media, for Theresa May and her government to blame the Kremlin. Unless the prime minister really does have firm information that the Russian state planned and carried out the attack, she should resist this pressure and the accompanying demands that the UK retaliate for a crime that is still under investigation.

Vladimir Putin is an authoritarian leader, who rebuilt a state that can be antagonistic and provocative, but it’s become exceptionally difficult to untangle well-founded allegations against Moscow from a daily onslaught of poorly evidenced, anti-Russian innuendo. There is a longstanding British tradition, dating back to at least the nineteenth century, of blaming Russia for almost everything and a failure to try to understand that country’s worldview has allowed relationships to deteriorate to the point that an objective assessment of the Skripal incident may not even be possible.

Since it emerged that Sergei and Yulia Skripal were poisoned by a ‘nerve agent’ in Salisbury, there has been a profusion of commentary suggesting that the Russian state is almost certainly behind the attack. Curiously, journalists who live and work in Russia are more cautious. In The Independent, Ollie Carroll portrays a more complicated picture, observing that Mr Skripal has many possible enemies who may have planned an assassination, without receiving an order directly from the Kremlin.

The journalist and author Marc Bennetts, who covers Russia for The Times and The Guardian, points out inaccuracies, inconsistencies and mistranslations finding their way into British reports. They’re not particularly difficult to find.

In 2010, The Daily Telegraph reported Putin’s comments, about a double-agent who exposed 10 sleeper spies, under the headline ‘Russian secret services don’t kill traitors’. Eight years later, the same remarks were dredged up again as a threat that ‘traitors will kick the bucket’. In today’s front page splash, The Times asserted that Theresa May was ‘set to hit back at Russia over spy death’. Mr Skripal is not yet dead. He’s in a ‘stable but critical condition’.

Some of the coverage flirts with overt Russophobia. This week, the Sunday Times’ lead story claimed that the Conservative Party accepts donations from ‘dubious Russians’ and it was hard to ignore the insinuation that more or less any Russian who is in a position to donate money could be dubious. It’s difficult to imagine the newspaper matching this adjective to another nationality so casually.

None of which is to rule out the possibility that Russia’s government was involved in attempting to kill Mr Skripal, who is considered a traitor in his home country. If that is the case, then a strong diplomatic response is certainly necessary. However, Mrs May should take meticulous care to establish the truth precisely because the prevailing climate is so fiercely anti-Russian.

The Kremlin has been blamed for everything from Brexit to coordinating football hooliganism in recent years, usually on completely circumstantial evidence. Many of the loudest voices are veteran conspiracy theorists, when it comes to Russia. Labour’s Chris Bryant, who chairs the all-party parliamentary Russia group and raised the possibility of England boycotting the upcoming World Cup, once ingloriously hounded fellow MP, Mike Hancock, for employing a Russian in his Westminster office.

Conflicts in parts of the former Soviet Union, like Georgia and Ukraine, are commonly portrayed in alarmingly simplistic terms, both by politicians and the media. The EU’s own report into the Georgian war in 2008 concluded that it was caused by Mikheil Saakashvili’s decision to attack South Ossetia, yet it is usually depicted in Britain as a result of unchecked Russian belligerence.

Most accounts of a complicated civil war in Ukraine see only an outcome of Russian aggression. There’s been a stubborn refusal to examine more closely the extraordinary events on Russia’s doorstep, where a democratically elected government was unseated by a populist movement urged on by the US and the EU. You rarely hear about the involvement of nationalist militia, who terrified Russian speakers and Russian citizens in eastern and southern Ukraine.

Relationships between the UK and Russia are now, frankly, terrible, and it’s common to hear one demonise the other, without caution or nuance. There has been a startling failure of diplomacy, which has been drowned out by hostility and fear-mongering. Unfortunately, the current government has contributed to this mood, by using the Russian ‘bogeyman’ to distract from its problems with Brexit, for instance, when Theresa May decided to make it the main theme of her Lord Mayor’s Banquet address, back in November. It’s not like there was a lack of other material to talk about.

Against this backdrop, she has a special responsibility to consider carefully Britain’s response to events in Salisbury. In particular, she must weigh the evidence very carefully before doing anything that is likely to cause more damage to relations between the UK and Russia. It might not win plaudits from the press, but leadership involves, not only acting decisively when necessary, but also knowing when not to act.