In response to the attack, May has announced a package of retaliatory measures against the Russian Federation. These measures include the expulsion of 23 Russian diplomats
who are considered by the British authorities to be undeclared intelligence operatives.
The British government was quick to reach the conclusion that the attempted assassination
was directed by the Russian state. Other than demonstrating that the poison used to carry out the attack was developed in the Soviet Union, the Prime Minister has provided very little direct evidence linking the Russian state to the events last week in Salisbury.
Yet May used robust language earlier in the week to signify her government's determination to respond to the Russian state's alleged activities. She said that the government would provide a "full and robust response" that would "counter (the) pattern of Russian aggression elsewhere."
As a result, observers will have been expecting a response proportionate to the crime Britain judges the Kremlin to have committed.
A "full and robust" response would impose significant costs on the Russian government and provide a forceful statement of the Prime Minister's determination to face down the threat posed by Russia.
So, was the package of measures she announced enough -- considering the magnitude of the crime that she judges the Russian government to have committed?
When talking about sanctions, it is useful to distinguish between impact and effectiveness.
Sanctions generate impact if they impose a significant cost on the other side.
Effectiveness, meanwhile, depends on whether the sanctions help the country imposing them achieve wider political objectives. For Britain, these objectives might include: seeking to alter Russia's foreign activities by imposing a credible punishment that will deter it from undertaking similar actions in the future; showing the British public that its government is able to provide a robust and proportionate response to the activities that the Russians are accused of undertaking; and demonstrating British determination and resolve to other countries.
In my opinion, it is unlikely that the British response will have much impact in Russia. Nor is the response likely to prove effective in helping the British government achieve its political objectives.
The greatest impact will be felt by the Russian intelligence services, which will undoubtedly suffer disruption due to the expulsion of the 23 suspected operatives. It is likely that the Russian government will later announce its own set of tit-for-tat measures in response.
Beyond this, it is difficult to see how the other measures will impact the Russian government. Other diplomatic measures, such as suspending high-level contacts with Moscow and withdrawing the British official delegation from this summer's soccer World Cup in Russia, are unlikely to cause sleepless nights at the Kremlin.
The formulation of so-called "Magnitsky laws," designed to target the assets of those accused of human rights violations in Russia, are also unlikely to have much impact.
Serving Russian government officials -- especially the most senior in Russian President Vladimir Putin's inner circle -- are unlikely to hold their assets in London anyway. And those who do will quickly move them elsewhere.
And while it is true that many wealthy Russians reside in London, most wealthy Russians do not commit human rights abuses in Russia. As such, they would be unaffected by the Magnitsky laws.
Greater efforts to crack down on illicitly acquired assets in London are to be welcomed. But it should concern British citizens that this hasn't already taken place -- both in relation to individuals from Russia and elsewhere. And, inevitably, legal complications will emerge if money-laundering laws are selectively applied to Russians.
If the impact of the Prime Minister's measures proves to be modest, then the effectiveness of government policy towards Russia may be compromised.
The Russian government is unlikely to alter its foreign policy on the basis of what it considers to be the "totally unacceptable, unjustified and shortsighted" actions of the Prime Minister.
And at home, the British public might also question whether a state-directed chemical attack on UK soil -- which is what the government has judged the Russian state to have committed -- warrants a stronger response.
Theresa May could have taken much stronger action. But instead she chose to impose low-cost and low-impact measures that are unlikely to generate much impact in Russia.