The Lithuanian capital of Vilnius is hosting the European Union's third Eastern Partnership summit, which many expected to be a major EU triumph because of the scheduled signing of an Association Agreement with Ukraine. The Eastern Partnership project was initiated by Poland (later joined by Sweden), for the gradual economic and political integration of six former Soviet republics into the EU. Though Armenia, Azerbaijan, Belarus, Georgia and Moldova are also part of the Eastern Partnership, Ukraine is seen as the "prize catch" by the EU.

If the EU could sign the Association Agreement, including ratification of free trade and visa liberalization deals, the Vilnius summit would become a milestone in the history of EU expansion, because despite not being equal to granting EU membership, the agreement is a key step toward integration into the EU.

But Ukraine has upset the EU's calculations by deferring the EU pact, ostensibly under Russia's pressure. And thousands of Ukrainians have taken to the streets demanding that their government go ahead with the past with EU.