Over 120 Kremlin diplomats have been expelled from a string of countries around the world after the nerve agent attack on British soil.
Today, NATO became the latest organisation to take action, axing seven diplomats and blocking the appointment of another three.
Ex-Ukrainian President Viktor Yushchenko, who himself was poisoned during a 2004 election campaign, welcomed the international response.
But he also warned Russian despot Vladimir Putin would stop at nothing to take out his enemies.
He told Sky News the poison attacks on himself and Mr Skripal were very similar.
And he warned: “Russia will punish everyone who opposes their political course.”
Asked about the expulsions he said: “If we are talking about Russian policy for the last decade or 15 years, it is dangerous.
“Of course we should talk about the diplomatic component, but we should talk about the military component, we should talk about the safety component, economic, financial.
“Let’s think, what is Putin most scared of? Solidarity, international solidarity.
“Look, the decision of 24 countries of the world to expel Russian diplomats is the most important story in the world.
“It is the most powerful blow delivered to Putin’s policy for months.”
He went on: “I have no doubt that Russia carried out the attack.
“I want western society, western governments and European governments in particular, to have no doubt too.
“I totally agree with the British position. I am glad that it has received international support and solidarity.
“I think politically it is a very important position that is being developed with a united Europe and the United States.
“But I don’t want it to end there with this single step, which we use to confront the modern imperial Russian policy.”
His comments come after Andrey Kortunov, Director General of the Kremlin-established Russian International Affairs Council, warned the worldwide action could be a tipping point into war.
Speaking on the Today programme, Mr Kortunov said: “By cutting these channel of communication, we increase risks of miscalculation.
“Maybe not clear interpretation of intentions of the other side. And basically, here it increases the dangers of inadvertent escalation or even a war.
“So, again, in my personal opinion, the expulsion of diplomats is not the best way to deal with the crisis because if we don’t talk to each other – how can we handle the crisis?”
Mrs May has hailed the “unprecedented series of expulsions” of Russian diplomats across the globe in the wake of the nerve agent attack in Salisbury.
The Prime Minister insisted the move sent a strong message to Moscow that it cannot ignore international law.
She said: “It is also important to note that our partners are not only taking these measures out of solidarity with the UK, but also because they recognise the threat that these Russian networks pose to the security of their own countries and the pattern of Russian aggression which has affected us all.”