The Importance of "Minor" Nations in World War I

There were a lot more nations than just Germany, Britain, England, Russia and the United States that fought in World War I- for example, Roumania, Ireland, Albania, Turkey, to name a few. Each of these countries probably supplied a number of troops to their respective sides, however, I believe that the biggest support that each of the minor nations supplied to their respective sides was an additional front to fight on. For example, had the "Big" nations alone been fighting the Central Powers, the only point of attack on Austria-Hungary would be fighting through Russia. However, with Italy, Serbia and Roumania as additional fronts, Austria-Hungary had to fight on three sides of its borders, dividing their troops out over a much larger area. Likewise, the fact that Bulgaria was allied with the Central powers prevented Serbia and Roumania from allocating all of their troops to the Austria-Hungarian front. Were it not for these smaller countries, allocation of troops would have been easier, especially for the Central Powers, and that could have given them the edge in the war.