The crisis could worsen social discontent and complicate collaboration with the European Union and Russia.

Changes to U.S. missile shield plans in Europe address only some of Russia's concerns.

Concerns about immigration are delaying discussion of the countries' admittance to the Schengen zone.

Both countries use demands for more autonomy by ethnic Hungarians in Romania as a political issue.

To achieve its foreign policy objectives, Bucharest must first settle its governmental affairs.

Running out of time for its pipeline to Europe, Moscow will need to offer concessions to Sofia.

The country will rely on foreign workers to offset the effects of population decline.

Eurozone integration efforts have been met with different responses from Hungary, Romania and Bulgaria.

A Russian spokesman suggested the breakaway region could join Moldova, but significant constraints remain.

The 17-member eurozone is slowly pulling away from the EU.