After World War I, though, the basic territorial pattern of the Balkans was set. Romania, Greece, Bulgaria, and Albania were independent countries and, with some exceptions, occupied their current borders. Today's countries of Serbia, Montenegro, and Macedonia were then part of Yugoslavia--a new country formed in 1918.
verb (used with object), undermined, undermining. 1. to injure or destroy by insidious activity or imperceptible stages, sometimes tending toward a sudden dramatic effect. 2. to attack by indirect, secret, or underhand means; attempt to subvert by stealth. 3. to make an excavation under; dig or tunnel beneath, as a military stronghold.
To diminish or destroy the province or effectiveness of; undermine: The partnership between the United States and Western Europe is undercut by diverging economic interests (Scott Sullivan). 2. To sell at a lower price than or to work for lower wages or fees than (a competitor).