It sounds like a plot from a spy thriller, but the death of a former KGB agent - recently poisoned in London - should prompt a reassessment of our relationship with Russia and the increasingly authoritarian Vladimir Putin.
The murky case bears Moscow's fingerprints. The victim, Alexander Litvinenko, was a critic of Putin.
He died after ingesting a large dose of polonium 210, a substance normally used as part of the triggering device for atomic weapons.
This is the latest in a series of thuggish episodes involving critics of Putin, who has steered the post-Soviet Russian state away from democracy toward his own brand of authoritarianism.
Putin has avoided some of the hallmarks of communism, such as forced collective farms, mandated atheism and the overheated rhetoric of class warfare. But he has asserted tight control over the government and he has seized power over important parts of the economy, including the oil industry and media outlets.
Nongovernmental organizations have been marginalized.
In May, Russia's last popularly elected governor was arrested. There has been a series of mysterious killings, most of which remain unsolved.
Putin's regime has signed major arms deals with Hugo Chavez's Venezuela, and Moscow is delivering advanced surface-to-air missiles to Iran to help that country protect its illicit nuclear weapons program.
Up to now, Washington and other Western governments have largely ignored the implications of all this. But at some point, we must accept the obvious - that Vladimir Putin's government is no friend of the West - and change our policy accordingly.