Already suffering under the impact of sanctions — tightened on Wednesday night by the US and EU — because of its annexation of Crimea, Moscow could be subjected to much more punitive measures if it is shown to be the source of the missiles used to target the civilian airliner.
Although responsibility for the attack has not yet been determined, initial suspicions were pointing at the pro-Russian rebel forces which have established strongholds in the east of Ukraine since the ousting of Viktor Yanukovych by protests earlier this year.
Separatist leader Igor Strelkov is reported to have boasted that his group shot down a Ukrainian military transport plane at around the time that the airliner, en route from Amsterdam to Kuala Lumpur, fell from the skies near the Ukrainian-Russian border.
However other militants in Donetsk, later insisted that armed forces loyal to the Kiev government were to blame.
Experts said that it was implausible to suppose that the rebel groups could have perpetrated the attack using a sophisticated ground-to-air missile system without Russian support.
“Of course at this stage it is still theoretically feasible that it could have been the Ukrainian armed forces, the rebels or the Russians,” said Jonathan Eyal, international director of the Royal International Services Institute in London. “But up to now there hasn’t been any instance of the Ukrainians having used their air defence system against aircraft for the simple reason that the rebels don’t have aircraft. The idea that this was mistakenly shot down by the Ukrainians is not plausible.
“It can’t be a rebel force on its own. They couldn’t have operated this system without Russian direct involvement.”