IN eastern Ukraine, Vladimir V. Putin has been playing with fire.

He has mobilized the worst elements to be found in the region. 

He has taken thugs, thieves, rapists, ex-cons and vandals and turned them into a paramilitary force. 

He has permitted ad hoc commanders of separatist groups to kill or chase off intellectuals, journalists and other moral authorities in the cities of Donetsk and Lugansk.

He has watched as a vodka-soaked rabble army destroys or takes over public buildings, hospitals, schools and municipal offices of the country it is pretending to liberate. 

He has allowed a veritable gang war to take hold — without caring that he is losing control of the forces that he has unleashed, with rival bands pitted against one another and carving out fiefs amid the growing anarchy.

Most troubling of all: To this underworld without structure or discipline, to these undisciplined louts who know only the law of the jungle, to this new brand of fighting force that has only the dimmest idea of war and no idea, God knows, of the laws of war — to this motley collection Mr. Putin, the Russian president, gave a terrifying arsenal with which the amateur soldiers were unfamiliar and with which they have been playing, like kids with fireworks. 

We know that Russia supplied vast quantities of heavy weaponry to the separatists and trained them to use the SA-11 surface-to-air missile system — the kind believed to have been used to bring down Malaysia Airlines Flight 17. 

One can envision the victorious gang celebrating with its trophy, playing with it as if it were a toy — one that can reach altitudes of over 70,000 feet.

One can similarly imagine Russian military officers — not so secretly assigned by the Kremlin to watch over the missiles and their use by amateur artillery crews targeting Ukrainian military aircraft — being overtaken by events and seized with panic. 

One can even imagine their consternation when Igor Strelkov, the self-proclaimed defense minister of the Republic of Donetsk, claimed responsibility for shooting down a Ukrainian military plane — which turned out to be Flight 17. 

We know what happened.

Whatever the outcome of the eventual investigation — an investigation made well nigh impossible by these dogs of war who follow no creed and no law, who, as they horrified the world by leaving the bodies of their victims abandoned in fields or heaped in poorly refrigerated train cars, as they reveled in their 15 minutes of fame by deploring before the news cameras of the world that the 298 lost souls had had the bad taste to “land” on people’s houses or in reservoirs used for drinking water, were also purloining the plane’s black boxes, organizing the export to Russia of possibly compromising debris, and casually stripping the bodies of objects of value — whatever the outcome of the investigation into all of this, an undeniable result was carnage, a war crime, an attack on Ukraine, the Netherlands and Malaysia all at once. 

For all of these reasons, it was hard not to side with Ukraine’s president, Petro O. Poroshenko — who, it is worth noting, has shown in the terrible days since the crash the qualities of composure, dignity and authority that he exhibited during his campaign for office — when he asked the international community to classify as terrorist organizations the “people’s republics” of Donetsk and Lugansk.

It is also hard not to agree with Mr. Poroshenko when, several hours after the tragedy, speaking unemotionally and with no trace of hate, he reminded France’s president, François Hollande, that Col. Muammar el-Qaddafi had been blacklisted by the world for his suspected involvement in a similar attack on a commercial airliner, Pan Am Flight 103, over Lockerbie, Scotland, in December 1988.

Faced with this new Lockerbie, will we in the West do no more than beg Mr. Putin to provide “free and complete” access to the crash site and offer “full cooperation” in the recovery of remains? 

Have we not a moral obligation to draw logical conclusions about a crime for which, because of his incendiary and irresponsible policies, deeply unworthy of the president of a great power, Mr. Putin is, in the end, wholly responsible?

Under the circumstances — with Mr. Putin having not yet agreed to back off in Ukraine, much less in Crimea — how can France morally justify its plan to deliver to Russia two Mistral-class warships, now being fitted out in the western port of St.-Nazaire? Do we want them to become the crown jewels of a Russian fleet off Sebastopol and, perhaps, Odessa?

To see the European Union acting so pusillanimously is very discouraging. France wants to hold on to its arms contracts for the jobs they are supposed to save in its naval shipyards. Germany, a hub of operations for the Russian energy giant Gazprom, is petrified of losing its own strategic position. Britain, for its part, despite recent statements by Prime Minister David Cameron, may still not be ready to forgo the colossal flows of Russian oligarchs’ ill-gotten cash upon which the City, London’s financial district, has come to rely. 

In European parlance, this is called the spirit of Munich — appeasement. And it is a disgrace.