I knew Sasha - as all his close friends called him - for more than five years. And after reading this intimate portrait by his widow, Marina, and his colleague Alex Goldfarb, the whole world can know him too, and understand why the finger of suspicion for his horrific poisoning last year points so directly at the Russian secret services and beyond to the Kremlin itself.
The political dynamite at the heart of this intensely moving testimony is not only evidence for the widely accepted belief that the FSB, the successor to the KGB, received a direct order from President Vladimir Putin for the assassination. It also demonstrates that the motive was Litvinenko's part in the worldwide dissident movement to bring to global attention the truth about the current Russian regime. This means many others are also in danger.
The text, which took four and a half months to write, records a conversation in 1999 between Putin and the oligarch Boris Berezovsky, before their fallout over a struggle for influence, in which the then head of the FSB wondered aloud about how "to get rid of" Litvinenko and the then prosecutor general, Yury Skuratov. The authors may be driven by a recent and very raw wound, but they are hardly the first to notice the parallels with the brutal shooting of the brave campaigning journalist Anna Politkovskaya - another friend of mine and a severe critic of the slide to vicious authoritarian nationalism in Putin's Russia. And, of course, there have been so many others - journalists, human rights campaigners and ordinary citizens - who have suffered in the dark where the spotlight of media attention does not fall.
This biography traces Litvinenko's life from when he joined the KGB at the moment that the Soviet Union was poised to collapse, and is especially personal in the account of how Goldfarb first met the Litvinenkos, when he helped them to escape to Britain via Turkey. From such a privileged perspective, the authors reveal that Litvinenko was a key witness to the FSB's role in both the 2002 Dubrovka theatre siege, when 129 hostages were killed, and the 1999 Moscow apartment bombings, in which 300 people were slaughtered. It was this outrage that provided the excuse for Putin to launch his violent crusade against the people of Chechnya.
In all the global news coverage of Litvinenko's poisoning last November, and now the attempts by the British authorities to extradite and bring to justice Andrei Lugovoi, the former FSB officer who is alleged to have administered the poison, the story of the oppression of Chechnya has received little prominence. Yet Chechnya is at the core of all the burgeoning problems that the west faces with Russia today, all too visible at the G8 summit in Germany earlier this month.
Since 1999, hundreds of thousands of Chechens have been displaced and more than 100,000 killed - most of them civilians. Disappearances, torture, rape, extrajudicial killings and the silencing of independent journalists and human rights defenders have been carried out daily, both by Russian forces and by the militia of Putin's puppet president there, Ramzan Kadyrov. Just 12 months before Litvinenko's murder, the United Nations Committee Against Torture expressed grave concerns about "reliable reports of unofficial places of detention in the North Caucasus and allegations that those detained in such facilities face torture or cruel, inhuman or degrading treatment". This year, the Council of Europe commissioner for human rights publicly deplored the continuing torture, and the European Court of Human Rights ruled in favour of the applicants in its first ever torture case from Chechnya, brought by the brothers Adam and Arbi Chitayev. Meanwhile, the Russian Supreme Court was denying an appeal against the closure of the Society for Russian-Chechen Friendship, an NGO based in Nizhny Novgorod, which has publicised many abuses against civilians throughout the Chechen conflict.
Those of us campaigning for human rights, peace and reconciliation in Chechnya can only hope that the high-profile publication of this work will help shed some light on the forgotten problems of our land. It should play a part in shaming the west out of its silence and its appeasement of a regime that challenges the very essence of our humanity.
This matters not just for Chechnya, but right now for the people of Kosovo, where Russia is blocking their claim to independence from Serbia, and of course the people of Russia itself, who must also have heard the rumours that Putin is currently plotting to extend his period in office, which should by law end in May next year.
Perhaps the tide is turning at last - or at least there appears to be growing interest. Columbia Pictures has already acquired the rights to turn Sasha's story into a Hollywood movie, with Johnny Depp in the lead role, which will bring the crime to a wider audience still. Maybe a good test is whether this important book finds a publisher in Russia.
Akhmed Zakayev is foreign minister of the Chechen government-in-exile