Ahead of this week’s Vilnius Summit, European diplomats should have no illusions about Russia’s next move.

Vladimir Putin is not going to stop at his success with Ukraine. Having pressured his Ukrainian counterpart President Viktor Yanukovich into rejecting a new EU association agreement with Kiev, the Russian president will be turning his attention to Georgia and Moldova.

These are the only two of six Eastern Partnership (EaP) countries that remain committed to signing the trade accord in Vilnius. Three other countries apart from Ukraine—Armenia, Azerbaijan, and Belarus—have already turned their back on the deal.

Georgia and Moldova are now faced with a very tough choice: either they can stick to their commitment to move closer to Europe and risk a fierce economic and trade backlash from Russia, or they can also ditch an association deal with the EU.

Dmitri Rogozin, Russia’s deputy prime minister in charge of the defense industry, has starkly warned against taking the first option. During a private gathering two weeks ago in Brussels that was attended by some of the EU’s top regional experts and diplomats, he was unashamedly threatening.

Rogozin said that Russia would close its borders to goods from any country signing the EU association agreements. Migrant workers would be banned from finding jobs in Russia.

Those are not idle threats; we saw when Russia─with the full intention of causing huge damage to its neighbor’s economy─stopped over 30 percent of Ukrainian exports destined for the Russian market. Georgia and Moldova are very much aware that Russia can use its energy sources and its big markets as weapons to make them toe the line, too. Their economies are not sufficiently independent of Russia, nor are their energy resources diverse enough to be able to deflect Russian blackmail.

The other option for Georgia and Moldova is to bow out from signing the EU association agreements. They know that without their big neighbor Ukraine in the European “club,” it will be extremely difficult for them to fend off intimidation from the Kremlin.

Moldova is particularly vulnerable to Russian pressure because of its breakaway region of Transnistria. There, a pro-Russian nationalist clique is doing its best, with the help of Russia, to undermine the Moldovan government’s pro-European moves. With Kiev in the Russian camp, Moldova has lost Ukrainian support to resolving this long-standing dispute.

Ukraine itself has squandered its chance to exercise strategic leadership in the region. As a neighbor of Moldova and with EU support, it could have played an important role in supporting Moldova’s claims to territorial integrity and in helping it with its border and customs management. That is no longer a possibility.

It’s not going to be easy for Georgia, either. The country’s new leadership does not want to forego its economic and strategic ambition to move closer to Europe, but it also wants to improve relations with Russia.

For the EU itself, the consequences are serious, too. If Moldova and Georgia end up not signing the EU accord, the EaP─already seriously damaged by Ukraine’s decision─will be dealt a fatal blow.

If Moldova and Georgia do sign, the EU will need to move quickly to counter any Russian backlash. That means both sides implementing the trade aspects of the accords as quickly as possible. Also, the EU could help supply Moldova’s energy needs via Romania.

Even beyond the EU, there is huge interest in what happens at the upcoming Vilnius summit. This was especially noticeable during the Atlantic Council’s annual Energy and Economic Summit that was held last week in Istanbul.

Armenian delegates were still trying to come to terms with their own government’s decision not to sign at Vilnius after Russia applied huge pressure on Yerevan. “Armenia’s leadership should have found a way not to miss this perhaps unique opportunity for beginning this Europeanization process,” said Salpi Ghazarian, director of The Civilitas Foundation in Yerevan. “Now look at how Putin dealt with Ukraine.”

Turkish diplomats admitted that they are in a privileged position because Ankara is negotiating to become a member of the EU. But they, too, were disappointed over Ukraine’s decision. Turkey was keen on the benefits of the EaP for its neighbors and for Ukraine. Better trade access and more efficient border controls would have benefitted the region as a whole.

Yet the most striking aspect of the debates in Istanbul was how attractive the EU still is to its Eastern and Caucasian neighbors. This is true not only for economic and trade reasons, but for political and social reasons too, with values playing a big role.

That political compass is still there. But it is no longer sufficient to counter Russia’s crude short-term manipulation of economic resources. Post-Vilnius will require a major rethink about how Europe may be able to counter that negative influence.