It was the day Moscow's dreams of empire cost European lives. It was the day the Kremlin lost its last vestiges of credibility. It was the day when it became impossible to continue even pretending that Vladimir Putin's regime was anything close to respectable.
It was the day the mask came off. July 17, 2014 was the day Russia became a rogue state.
It wasn't just that the downing of Flight MH17 killed 298 people from 10 countries and four continents. It wasn't just that 80 of the victims were children. It wasn't just that the Netherlands alone lost 193 people, the largest Dutch loss of life since World War II.
And it wasn't even that Russia made this all possible by, according to all credible accounts, providing pro-Moscow separatists with a sophisticated BUK surface-to-air missile system capable of shooting down a civilian airliner flying at an altitude of 10,000 meters.
That was all bad enough. But it was what came after that really sealed it.
There was the disrespect the pro-Moscow rebels showed to the victims' remains -- the images of separatist fighters, smiling with cigarettes dangling from their lips, rifling through and looting the belongings of the dead.
And as the evidence poured in -- audio recordings, satellite images, and forensic data -- showing that the aircraft was almost certainly shot down by a surface-to-air missile fired from rebel-held territory, there was the obfuscation.
There was the Kremlin's formidable disinformation machine adding insult to injury by cranking out a dizzying barrage of crackpot theories about who really shot down the plane. And with this there was the realization that not only was Moscow responsible for a terrible tragedy, it was mocking the world -- and the victims -- in its aftermath.
MH17, of course, did not change everything. Russia's war on Ukraine continues. Crimea remains annexed. Pro-Moscow separatists and Russian troops are still in Donbas. And nobody has been held accountable for killing nearly 300 people.
But MH17 did change a lot. European leaders, most notably German Chancellor Angela Merkel, who had been inclined to work with Putin and give him the benefit of the doubt, turned into harsh critics.
Russia was transformed from a troublesome -- and often tiresome -- partner you could do do business with into a potentially lethal problem that needed to be addressed.
According to the Pew Research Center, attitudes toward Russia in the European Union -- which were positive in 2013 -- tanked in 2014 and 2015.
Russia is now not viewed favorably by more than one-third of the population in any single NATO country, according to Pew.
These trends did not start on July 17, 2014, they commenced in earnest months earlier when Russia annexed Crimea. But they accelerated as a result of that day and its aftermath.
After MH17, it became a lot harder to be a Putin apologist. And a lot easier to be a critic.
And one year after that ill-fated flight crashed into the sunflower fields of Donetsk Oblast, Russia is coming under renewed pressure over the tragedy.
An investigation by Dutch authorities that has been distributed for review by agencies in numerous countries will pin the blame for the tragedy squarely on pro-Moscow separatists in eastern Ukraine, CNN reported, citing officials who have seen the text.
And Malaysia, which lost 43 citizens on MH17, has drafted and circulated a UN Security Council resolution that calls for an international tribunal.
This puts Russia in a difficult spot.
Vetoing the resolution, as Russia has vowed to do, would be tantamount to an admission of guilt. Putin's protestations in a telephone call with Dutch Prime Minister Mark Rutte that a tribunal would be "premature and counterproductive" don't really have a lot of traction.
And in the unlikely event that Moscow pulls an about-face, supports the resolution, and allows the tribunal to proceed?
Well that opens the door to some very uncomfortable questions being asked in open court. Not just about the pro-Moscow separatists, but about who in the Kremlin leadership approved giving them a surface-to-air missile system.
MH17 is already a watershed. And it could well turn out to be Vladimir Putin's Lockerbie moment.
NOTE: Be sure to tune in to the Power Vertical Podcast on July 17 when I will discuss the issues raised in this blog with Han ten Broeke, member of the Dutch parliament and spokesman for its Foreign Affairs Committee; James Miller, managing editor of The Interpreter magazine; and Andreas Umland, a senior research fellow at the Institute for Euro-Atlantic Cooperation and a professor of Russian and Ukrainian history at Kyiv Mohyla Academy.