The second narrative reads the crisis more closely through Ukraine, seeing the grab for Crimea more as a one-off desperate move by a Russian leader who panicked that he was losing his closest neighbor. If this is the case, then the immediate crisis will be contained in Ukraine's borders and the rest of the neighborhood has nothing to fear—for now at least.

In support of this argument is the fact that Putin make a border agreement with Estonia only last month. Why do that if he was planning to destabilize the Baltic States?

Of course the real story may contain elements of both of these versions. But a key test of what happens next is Moldova, the post-Soviet country most vulnerable to a second application of a new “Putin doctrine,” if it exists.

Why Moldova? Georgia is also nervous but is less exposed, as Moscow effectively already burned its last bridges with Tbilisi in the war of 2008.

Moldova has pressed ahead the fastest of the six Eastern Partnership countries toward integration with the European Union. Its citizens are now one step away from visa-free travel to the European Union and are set to get an Association Agreement with Brussels this summer.

But the country also still gets all its gas from Russia—unlike Georgia. It has tens of thousands of migrant workers in Russia. It is politically fragile. The pro-European government is a loose coalition, with the pro-Russian Euro-skeptical Communist Party remaining the largest party in parliament.

Then there is Transnistria, the breakaway territory on the left bank of the Dnestr River that has been de facto separate from Moldova and a Russian military protectorate since the conflict of 1991. Unlike Abkhazia and South Ossetia, Moscow did not recognize the territory as independent in 2008.

Returning from talks in Washington last week, Moldovan Prime Minister Iurie Leanca warned the Crimean situation could be “contagious”—an obvious reference to Transnistria.

Transnistria is a pet project of super-patriotic ideologists in Moscow. Some of these usual suspects, such as Mikhail Leontyev, have been broadcasting on its behalf recently.

All true—but thus far both Moldova and Transnistria have been quiet, while the crisis rages next door. Perhaps this is because the Transnistrians themselves are less interested in trouble than their would-be champions in Moscow. Transnistria's de facto foreign minister Nina Shtanski was excessively cautious last week, saying only, “We hope that the situation [in Ukraine] is stabilizing.”

Transnistria has reasons to want to keep its options open. Ukraine is close and Russia is far away, so it is vulnerable to a repeat of the economic squeeze it last suffered from Ukraine in 2004-2006. Its people also know that the ace of Russian recognition might not be such a winning card after all, as a lot of Moldovans would be prepared to sacrifice Transnistria in return for faster integration with the EU.

Moldova needs watching closely, very closely. There is a danger of over-spill and there are people in Moscow who might want to provoke a crisis in Transnistria anyway. But it looks as though neither party on the ground is looking for trouble. In the case of Moldova's pro-European parties, they also have another challenge coming up later in the year—trying to win a parliamentary election in which Russia is bound to be spending a lot of resources.