On Thursday, in a Pulitzer-worthy piece, BuzzFeed journalists reported on Russia's long-term assassination campaign in Britain.

It's true: The activity of Russian assassination squads in Britain has been a known quantity for a while now. As I noted in March 2015, Putin has been highly active, and deliberately semi-overt, in killing his domestic and foreign critics. He has sent a message that his reach is truly global.

Still, BuzzFeed's reporting is the most substantial thus far produced. And that makes it a huge embarrassment for the British government. Indeed, BuzzFeed has almost certainly now been given what the U.K. government terms a DSMA-03 notice.

But that's the background. What about the context?

Well, for one, many American readers of the BuzzFeed report might be wondering why Britain ignores Russian assassinations on its soil. After all, they might ask, aren't the British supposed to be a bulwark against Russian aggression?

Sort of.

Yes, the U.K. is a longstanding U.S. ally in intelligence operations against Russian targets. And yes, at the U.N. and in the E.U., Britain often takes the diplomatic lead in pushing for tougher sanctions against Russia. Yet, that's just one side of the coin.

On the other side is the influence of Russian money on the British establishment. And it's a huge influence.

The story of that influence begins in the years that followed the collapse of the Soviet Union.

With a mixture of insider deals and kickbacks, many Russians bought huge chunks of valuable state industries. Life for these individuals was very good. But from 2002 onwards, Putin began to centralize more and more power. In turn, the power balance shifted. Wealthy Russians realized that if Putin desired, he could make their lives a living hell. Or simply kill them. Their money was no longer safe.

London was the answer.

Desperate to attract capital investments to boost the British economy, the U.K. government embraced external capital. That meant Britain, rather than the U.S., for example, was an ideal place for Russians to set up shop. No questions were asked about how a foreign investor came about his millions. And so, the British capital and its suburbs became a playground offering safety, glamor, luxury, and a degree of separation from Putin's cold grasp.

Putin was also happy with this arrangement. It meant isolating prospective political opponents and earning influence with the British government. The one rule for Russian expats?

Don't criticize the Tsar.

And one way or another, that's what the dead in BuzzFeed's article did. Directly or indirectly, they challenged Putin's authority or threatened his dominion of power. So Putin had them killed.

Of course, that leads to the second question: How did Putin kill so many people on U.K. soil without finding repudiation?

The answer is thinly veiled cutouts.

More specifically, as the 2000s progressed and more Russian money flocked to Britain, Russian organized crime assumed a larger role in the city's émigré life. Money laundering was the primary benefit that London offered. After all, the high price of London property is of great appeal to organized criminals. It offers a safe investment and quick clean of very dirty money.

But where Russian organized crime goes, Putin's influence follows. Russian criminals know that Putin is the Tsar. To operate effectively and sustainably, they kneel to the throne.

And that's where the British government lost its gambit.

Because unlike the FBI in the United States, Britain's counter-organized crime authorities are weak. Although there are very good (and courageous) men and women in the units that do exist, there are also corrupt officials. That's one element that BuzzFeed leaves out.

Part of the reason why the U.K. government has not been able to restrain Russian intelligence is that it is has not been able to restrain Russian organized crime. Too often, the criminals are one step ahead of the game. And that matters for the assassination problem, because when it comes to the killing game, the Russian state and organized crime groups are inseparable. The Russians are not stupid. They use organized crime networks both to conceal their responsibility for assassinations, and as logistics nodes to carry out assassinations. Sending diplomats from the embassy, for example, is too public. And they know that absent action from the Metropolitan Police's organized crime section, MI5 will stay in the shadows.

Nevertheless, the ultimate problem here is the toxic mix of money and political resolve. Considering the risks to investment and the appeal of relative calm with Moscow, successive British governments have shut their eyes to the calibrated murder.

The crunch point was 2006, when former Russian intelligence officer, Alexander Litvinenko, was assassinated under Putin's orders. The U.K. knew Putin was responsible but did nothing. In turn, the Russians knew that if they could kill Litvinenko without considerable riposte, then anything was possible.

To Putin, that acquiescence was blood to a shark.

And so are where we are.