LONDON - Russian President Vladimir Putin has sought to shift the blame on Ukraine for the destruction of Malaysia Airlines flight MH17 over Ukraine's war-torn eastern regions.
While Mr Putin did not identify any culprits for the disaster, he told officials in Moscow on Thursday that the tragedy "wouldn't have occurred if there had been peace on this land and hostilities hadn't renewed in Ukraine".
Still, evidence continues to mount that local rebels tied to Moscow were responsible for the destruction of the MH17 plane, and that they used sophisticated weapons supplied directly by Russia.
Civilian aircraft at a regular cruising altitude of 10 kilometres - as the MH17 was at the time when it was brought down, almost two hours into its flight out of Amsterdam in the Netherlands - are not easy targets.
They cannot be hit by shoulder-held missiles or anti-aircraft artillery which are out of range, they are only vulnerable to precision weapons such as the BUK missile batteries which are in the Russian military service, but which were also supplied to all of Russia's neighbours. And, while the BUK missiles are mobile and do have their own operating radar, they rely on more integrated radar systems to hit a faraway target like a civilian airliner.
Since these are only available to states rather than various rebels and since the fighting in Ukraine is not officially between governments, the assumption was that global civilian aviation was safe from the internal civil war which has disfigured this country since February.
That is why neither national nor regional flight control agencies, nor bodies such as the International Civil Aviation Organisation ever advised airlines to avoid fights over Ukraine; after all, no overflight ban is enforced over Afghanistan, a country which has experienced a decade of far bloodier military confrontations.
What appears to have happened is that pro-Russian rebels mistakenly aimed at the MH17 flight, probably in the belief that it was a Ukrainian military transport jet of the kind they regularly attack. But it's impossible to believe that they could have successfully hit their target without radar and other logistical support from the Russian military which, again, was probably unaware of the plane's real identity. US intelligence agencies, which hold the largest quantity of electronic evidence available to piece together the final minutes of flight MH17, privately concede that this explanation is the most likely.
But it's in nobody's interest to rush in identifying the culprit for the disaster, partly because the interpretation of the available evidence takes some time, partly western intelligence agencies are loath to reveal all their analysis methods and sources, but also because Western governments need to figure out what would be their next steps, should they end up blaming Russia and its proxies for the carnage.
The result is that Western governments led by the US are beginning to whisper allegations against Russia, but still won't publicly lay the blame for the disaster on Russia.
Meanwhile, the race is on to collect as much evidence on the scene of the disaster as possible. But that, too, is easier said than done. For the area in which the MH17 plane crashed is also one in which pro-Russian rebels operate, and some of them may now try to hide material evidence: there are persistent rumours in Ukraine that rebels have already spirited away key bits of evidence, such as the plane's "black box" which records every action undertaken by the crew before the crash.
Still, incriminating evidence against Russia keeps popping up. Igor Strelkov, the Russian rebels' commander in the area where the plane was hit, is on record as boasting about the downing of what he considered to be a Ukrainian aircraft at about the same time as the destruction of the MH17 flight.
The Ukrainian authorities have also released a recording of a phone conversation between ethnic rebels and their patrons back in Moscow, in which they appear to admit to the destruction of the Malaysia Airlines plane. But there is no independent confirmation of the accuracy of these recordings.
Later on Friday, the war of words between Ukraine and Russia is likely to intensify, with each side blaming the other for the disaster. Meanwhile, tensions are also likely to rise between Russia and the West, as governments will start demanding the launch of an impartial investigation into the tragedy, complete with powers to interrogate local officials.
But, ultimately, the real debate is not so much about producing the right evidence and culprit, but more about what can be saved from the rapidly-deteriorating relations between Russia and the West.