The story gaining the most traction boils down to this: after the Kiev government had moved massively against the separatists, and drove them out of their stronghold in Slavyansk, Russia stepped up cross-border supplies of heavy armaments to the insurgents, in an effort to restore the balance. This has since resulted in the downing of several Ukrainian military aircraft. The Malaysian Boeing, the conclusion is, was shot by the rebels, and by mistake.

Publicly, President Poroshenko has already blamed the Russia-supported separatists, and President Putin has put the blame on the Ukrainian government's resumption of the military operation in the east of the country. Actually, these statements may be less contradictory than they appear, but this is small comfort. Whatever the final result of the investigation, Russia is likely to face a major political and media campaign reminiscent of the 1983 shooting of the Korean Air Lines off Sakhalin island, which ushered in the most dangerous period of the Cold War after the Cuban missile crisis.

The coming UNSC debate is likely to be emotional, and acrimonious. The US Congress may press President Obama to ramp up the sanctions which he had only announced less than 24 hours before the MH17 tragedy. The daylight between the United States and the EU approaches to anti-Russian sanctions may narrow. Russia's outreach to Asia beyond China may be compromised. This will put Moscow in a difficult spot, and prompt a reaction on its part.

The only sensible step now would be to stop the fighting in Ukraine immediately and begin a political process, under the OSCE auspices and led by the Contact Group. The tragic and sudden loss of so many innocent lives should put a final point to the armed conflict. Or it may put the international conflict over Ukraine on a much higher and more dangerous level. The choice is still to be made, but the time is running out fast.