The more I probed, the more I was becoming convinced that Sasha Litvinenko had been poisoned by a group of people independent of the Kremlin but with close connections to the Russian security forces. The sophisticated planning behind the plot and the evidence of the poison factory strongly suggested the fingerprints of an FSB-style operation; the parallels with former crimes linked to the organization were too strong to be ignored. This did not necessarily mean the FSB had been acting in its own interests or on its own initiative; the security forces were so fragmented and out of control in the years following 1991 that individuals and groups within them were constantly taking on moonlighting jobs on behalf of paying customers. Today's security agencies are not homogeneous; they are composed of people with widely differing interests, and the unspoken truth is that neither the director of the FSB nor Vladimir Putin nor indeed any other Kremlin leader can be sure he controls them all (or even knows what they are getting up to).
I considered the possibility that a wealthy client or clients who had fallen out with Litvinenko over a commercial dispute might have hired FSB agents to carry out a hit for them. The idea was not impossible and if the murder had happened on Russian soil, I would certainly not have dismissed it. But the international aspect of the killing, specifically the fact that it was in a west European country, troubled me. Even the most reckless agent offered the highest fee would think very carefully before accepting it. The FSB may be home to some very ruthless people, but they are nonetheless professionals; they would know that the murder of a British citizen on British soil would inevitably stir up a hornets’ nest of public interest and trigger an investigation by a police force which is not open to being threatened or bought off. For professionals with security service credentials murder in Russia was child's play; FSB-connected contract killings were rarely investigated and almost never solved. But accepting a commercial commission to kill abroad was an entirely different matter. The risk was just too great.
Amid the faded grandeur of my room at Moscow's once magnificent Hotel Budapest I sat and reviewed the evidence I had gathered. I listened to the recorded interviews and notes I had amassed, and I weighed the theories I had been offered by interested parties and impartial observers alike. I was coming to the end of a very long road, and my thoughts on the Litvinenko affair were slowly crystallizing into what I considered the only feasible explanation for the crime that had taken place 1,500 miles from here in the heart of London. By the end of the evening and with a bottle of Stolichnaya half empty, I knew I was looking for a group of killers with FSB connections. I knew it was a group with its own reasons to target Litvinenko, a group that could advance FSB interests to justify the murder, interests that would confer at least some immunity on it if the Kremlin were to become aware of what it had done.
I looked again at the Federal Laws of July 2006 and considered what my thoughts would have been if I were a former colleague of Sasha Litvinenko, if I had been biding my time waiting for the opportunity to avenge myself for the wrongs he had done to the service both before and after his defection to the West. It struck me forcefully that Litvinenko was right: the wording of the law -whatever the Duma's intentions in passing it – can be interpreted as justifying the assassination of Russia's enemies overseas. If I were one of the many FSB men who had suffered as a result of Litvinenko's actions, it would have looked like a golden opportunity to kill him with at least some pretence at legality. If I had to make a dispassionate assessment of all the possible consequences of such an act, as all security men are trained to do, I would say to myself that even in the worst case of being fingered for the murder I could argue that I acted in accordance with the law. My defence would be that Litvinenko was a traitor who had damaged the interests of the service and of the Russian state. Such a defence could not be advanced for a commercial assassination. It was a compelling consideration and it pointed me in a very specific direction.