Britain has made the first move, and now the ball's back in Russia's court.
Prime Minister Theresa May is expelling 23 Russian diplomats after Russia refused to provide an explanation for the Salisbury nerve agent attack.
However, the UK is quickly running out of measures to take against Russia over the nerve agent attack.
Theresa May says it's the biggest single expulsion in more than 30 years.
Former EU ambassador to Moscow Michael Emerson told Kate Hawkesby it's also one of the few cards the UK has to play.
"The rest of the agenda is frankly speaking, not very impressive in terms of its operational effects. Russia will not be frightened by the Royal family boycotting the opening of the [Football] World Cup.
"It is predictable that Russia will expel 23 British diplomats if they have 23 diplomats in Moscow."
When asked if it was like Russia was being hit with a wet bus ticket, Emerson agreed.
May is also considering other measures, including boycotts but the UK has already decided against blocking the Kremlin's Russia Today network.
"One can presume that London decided not to do that because Russia would have kicked the BBC off its airwaves."
Sergei Skripal and his daughter Yulia remain critically ill in hospital, more than a week after the attack.
LISTEN ABOVE AS MICHAEL EMERSON SPEAKS WITH KATE HAWKESBY