Britain and Russia have entered a phase of a tit-for-tat expulsion of diplomats across the Atlantic; yet this is only the surface of a sinister issue.

Theresa May’s robust announcement to expel 23 Russian diplomats for the attempted murder of Sergei and Yulia Skripal in Salisbury has swiftly been retaliated by the Kremlin which has signalled its intent to expel British diplomats from Moscow.

The reality is chilling ~ a chemical weapon has been used on a British street. On closer reflection, the British Prime Minister had little or no option, and it is now pretty obvious that the provocation for the attack was to ignite a diplomatic row with the UK.

She has made it obvious too that Russia was responsible for the incident, arguably to whip up patriotic fervour within Vladimir Putin’s domestic constituency.

And not the least because the Russian President is seeking re-election this Sunday. Not since the disintegration of the Soviet Union (August 1991) has the equation between Moscow and London or indeed the West plunged to the level it now has.

Mrs May has effected a carefully calibrated response, both diplomatic and economic. Aside from the expulsions, Britain has targeted financial assets.

The primary objective is to establish the culpability of the 23 diplomats, who have already been identified as what they call “undeclared intelligence officers”.

The action has been unilateral, and it is open to question whether Putin will attempt a change in foreign policy in the aftermath of the British reprisal.

While Nato allies and the European Union have expressed solidarity, it is as yet uncertain whether the Western powers will act in concert to counter the Kremlin.

Has Putin taken advantage of the lack of cohesion within Europe over Brexit ~ Mrs May’s watershed initiative? If indeed Europe becomes a geographical expression, a coordinated response in matters diplomatic cannot be contemplated quite yet.

Suffice it to register that Mrs May has hinted at the Kremlin’s responsibility, if Wednesday’s statement in the House of Commons is any indication.

Most importantly, she has mentioned the “complete disdain, sarcasm, contempt and defiance” in official Russian responses to British requests for an explanation as to how a nerve agent developed by former Soviet weapons facilities came to Salisbury.

The plot is palpably more complex than what has been unravelled thus far. The diplomatic confrontation with Moscow is bound to escalate, clothed suitably with a bout of obfuscation and misinformation directed at Britain.

This, precisely, has been the Kremlin’s modus operandi. What matters most of all is that Britain has been targeted with a chemical weapon ~ criminally outrageous to say the very least.

Sergei and Yulia Skripal merely personify the hideous malaise… now in evidence from Syria to Salisbury. Mrs May has realised that the incident lends no scope for equivocation, given the sinister nature of Putin’s regime.