There is a grim logic to the shotgun referendum in Crimea that leads toward an expansion of Russia's land grab into eastern and southern Ukraine.
On its own, however, Russia's seizure of Crimea would risk unifying the rest of Ukraine against Russian aggression -- and in favour of integration with the European Union. In gaining Crimea, Russian President Vladimir Putin might lose the bigger prize: turning Ukraine into the real country that in 2008 he told former U.S. president George W. Bush it wasn't. That is something he will want to prevent.
In Crimea, Putin has kept his options open and western leaders off balance with his otherwise absurd insistence that the Russian troops on the ground are not Russian. Even now, he could conceivably stop short of annexation. He seemed to change his mind as things progressed: The referendum date was changed twice in the space of a week, and giving Crimeans the option of joining Russia was added to the ballot only 10 days before the vote.
Should Putin choose to escalate by moving troops into Ukraine beyond Crimea, even Germany has pledged to hit Russia with painful sanctions. This would damage the economy seriously: Former Russian finance minister Alexei Kudrin has forecast $50 billion in capital flight per quarter this year "in a mild scenario."
And yet sanctions too can add to the logic of escalation. Serious economic sanctions would, as the most fervent Soviet diehards and Russian nationalists have been hoping ever since the 1990s, create a full break with the West and return Russia's economy to a less extreme version of its Soviet-era isolation -- or, in their view, self-sufficiency. Sanctions would also force corrupt businessmen either to repatriate their ill-gotten gains or flee the country. The "liberals" who have, according to conservatives, held the country ransom for private gain since the collapse of the Soviet Union and prevented Russia's return to greatness would be routed.
The West would then have done its worst, while proving it is unwilling to go to war with Russia in order to prevent Putin from sending troops into his non-NATO neighbours. Any future land grabs would incur smaller additional costs for Russia.
Such a gathering of Russian lands is a 19th-century fantasy that would condemn Russians to relative penury in the 21st. The damage already inflicted on the country's currency and stock markets, and Russia's 13-to-1 isolation in a United Nations Security Council vote on Crimea (China abstained), demonstrate the threat. And yet Putin appears willing to accept a substantial economic cost.
There are a few markers to watch in gauging Russia's intentions. One of them is military. In addition to large-scale military exercises, Russian helicopters Saturday dropped troops just over Crimea's border with the rest of Ukraine to secure a natural gas facility. This may have doubled as a test of Ukraine's defences and responsiveness. More exercises and probes of this kind would be one indicator.
A continued expansion of provocations in eastern Ukrainian cities such as Kharkiv, Donetsk, Lugansk and Odessa would be a second. The same opinion polls that demonstrate Russians' desire to reclaim Crimea show a clear majority opposed to going to war in Ukraine. More dramatic incidents in which Russian-speakers in Ukraine are portrayed as in mortal danger would help to make that case.
Within Russia, a sustained campaign of propaganda referring back to the Second World War -- known to Russians as the Great Patriotic War -- would also be a sign. What in Ukraine and the Baltic states are understood as liberation struggles are to many Russians offensive, because they put in question the narrative in which the Soviet armies liberated these countries from Nazi Germany. This drip-feed of hate has already begun on Russia's tightly controlled television channels.
None of this proves Putin has made up his mind whether to invade eastern Ukraine, or even that he will formally annex Crimea. He may also be using fear of invasion to force the authorities in Kyiv and their U.S. and European backers to cave to Russian demands. Yet as with Crimea, amid the uncertainties, events are creating their own momentum.
"We would want to be sure we are welcomed with flowers" before annexing any territory in eastern Ukraine, Kremlin analyst Sergei Markov said Saturday. It appears arrangements are already being made.
Marc Champion is a Bloomberg View editorial board member.