British prime minister Theresa May is expected to address Parliament this afternoon on what the government plans to do to punish Russia for the attempted assassination of Sergei Skripal and his daughter Yulia in Salisbury nine days ago.

Authorities say a Soviet-era nerve agent was used to poison Skripal, who clings to life in a British hospital.

May had given Russian president Vladimir Putin until midnight last night to answer questions about the assassination.  This morning, a Kremlin spokesman called the accusations "baseless," and Putin threatened to respond to any sanctions with equal force.

CNBC:

Now, the ball is in the U.K.'s court and it has to decide what retaliatory measures it will take.  On Tuesday, May said the government was "ready to take much more extensive measures" against Russia, beyond the commonplace expulsion of diplomats, visa freezes and suspended security cooperation.

Having already predicted correctly that Russia would miss the deadline, experts at research consultancy Eurasia Group believe the U.K. will try to freeze assets of Russian individuals and entities.

"May will ... have to show readiness to use the one piece of leverage the U.K. public believes she has over Russia – the ability to freeze the U.K.-based assets of Kremlin-connected Russian elites," analysts Charles Lichfield, Jason Bush, Mujtaba Rahman and Alex Brideau, said in a note Tuesday.

"May will also confirm that there will be no official U.K. government presence at the World Cup and suggest that a fully-fledged U.K. boycott is still possible, depending on what is discovered in the Salisbury investigation.  Finally, there will probably be a classical expulsion of Russian diplomats," the analysts said.

Meanwhile, U.K. Finance Minister Philip Hammond suggested at the weekend that the U.K. could create legislation that bans individuals from entering the U.K. and access to its financial system, similar to the "Magnitsky Act" in the U.S.  The U.S. has punished Russian officials that it believes are responsible for the death of Russian tax accountant Sergei Magnitsky in a Moscow prison in 2009.

So far, the E.U. and U.S. are giving the U.K. strong support.  But practically speaking, May can do little to hurt Putin or Russia.  Any sanctions would be almost symbolic.

What is to be done about Vladimir Putin?  He is a prideful man, somewhat paranoid, and a compulsive liar.  Beyond that, he is apparently a vindictive sort who doesn't hesitate to strike back at those who cross him. 

But is he really responsible for the dozens of murders of political opponents?  Surely, some deaths attributed to Putin are coincidence.  Just yesterday, a former political foe of Putin was found dead in his home.  Nikolai Glushkov, a close friend of  former Putin crony Boris Berezovsky, died of unknown causes, and the British are treating it as a possible assassination.  But Glushkov was 68 years old, and it's more likely he died of natural causes.

By the way, Berezovsky hanged himself in his London home in 2013.

So Putin's foes keep ending up dead.  But it would be interesting if someone compiled a list of prominent deceased Putin-supporters over the same period.  My guess is that Putin is certainly responsible for some of the murders.  Russian intelligence may be responsible for others.  Still others may have been murdered by the Russian mob.  And a few were unrelated to politics.