All the ways Theresa May could retaliate against Russia for the poisoning of Sergei Skripal

LONDON - Prime Minister Theresa May has given the Russian government until midnight on Tuesday to provide a "credible" explanation for the poisoning of Russian double agent Sergei Skripal, after which she will "set out the full range of measures" Britain will take in retaliation.

So what are the options open to May? Here are all the possible responses the UK could take and how likely they are to take them.

Expel Russian diplomats

Britain last expelled Russian diplomats back in 2012 following "evidence of activities by the Russian intelligence services against UK interests." Such expulsions are relatively common in international diplomacy and are normally the first port of call in any major diplomatic incident.

How likely is this?

It is highly likely that at least some Russian diplomats will be kicked out by Britain. However, Britain will want to retain some diplomatic ties with Russia on UK soil.

Withdraw UK government representation from the World Cup

There was some excitement last week when Foreign Secretary Boris Johnson appeared to suggest that the England football team would withdraw from the upcoming World Cup in Russia. However, Johnson's aides quickly scrambled to clarify that he had only been referring to UK officials and diplomats withdrawing from the tournament, rather than the team itself.

How likely is this?

It is now fairly likely that Britain will withdraw its formal representation from the World Cup in protest over the Salisbury attack. However, it is questionable how seriously the Russian government will take Johnson and Prince William failing to turn up to the games.

Withdraw Russia Today's license

May was asked repeatedly in the Commons yesterday about the continued presence of the Russian state television channel Russia Today, in the UK. While criticising those politicians, including Labour leader Jeremy Corbyn, who have appeared on the channel, she did not explicitly state that their license would be withdrawn.

How likely is this?

Any decision about the licensing of RT will be taken by the independent communications regulator Ofcom, rather than May's government. However, Ofcom has already indicated that they may withdraw RT's license. In a statement released last night, a spokesperson said that:

"We have heard the Prime Minister's statement in the House of Commons this afternoon and we await her further statement on Wednesday. We will then consider the implications for RT's broadcast licenses."

It is, therefore, looking increasingly likely that RT could lose their license.

Cyberwarfare

Home Secretary Amber Rudd has previously raised the possibility of Britain taking retaliatory cyberattacks against Russia, following their attempts to meddle in Western elections. This could take the form of denial of service attacks against Russian state websites, or websites used to spread Russian government propaganda. This would be a relatively easy step for the UK to take but would mark a significant ramping up of tensions with the Russian government which could spiral into a highly damaging and costly cyberwar between the two countries.

How likely is this?

The risks associated with such attacks may prevent any immediate UK cyber-attack on Russia and so is not highly likely at this time. However, the UK government is keen to raise the threat of such attacks and this is likely to remain a tool in Britain's arsenal which they would be willing to openly use for the first time against another state.

Freeze assets of Russian oligarchs

May was under pressure yesterday to consider a UK version of the US Magnitsky Act, which would allow the UK to freeze the assets of Russian oligarchs in the UK. In recent years, London has become one of the world's most popular homes for wealthy Russians, many of whom have huge business interests in the UK. As Labour leader Corbyn pointed out in the Commons yesterday, wealthy Russians have also become major funders of May's Conservative party. The government, therefore, has so far been resistance to mimicking the US in clamping down on Russian money in the UK.

How likely is this?

The Conservative government has so resisted all requests to tackle Russian money in the UK. That could change after the attack in Salisbury. However, there has been little sign since the attack that this is one of the priorities for May.

International retaliation

There are very limited options available for the UK to take against what is the second largest nuclear-armed state in the world. So, if there is going to be a serious response to this attack, then it will have to be taken on a European or Nato level. In a call last night, French President Macron "offered his solidarity with the UK" according to Downing Street and the two leaders "agreed that the French and British governments should coordinate closely as the investigation developed and following Russia's response." Nato also released a statement last night saying that "the use of any nerve agent is horrendous and completely unacceptable. The UK is a highly valued ally, and this incident is of great concern to NATO."

How likely is this?

It is possible that Nato could ramp up its presence in the East in retaliation against Russian aggression. However, it is reasonable to doubt how willing the international community will be to actually take such decisive action against Russia off the back of this one incident. As a senior security analyst for Stratfor's Threat Lens, Ben West, told Business Insider, while there may be sanctions imposed against Russian officials it remains "highly unlikely" that the alliance will go beyond this.