In wooing Romania to the "Allied" side in World War I, the "Entente" powers promised Romania not only post war territorial gains, but to "supply" the country's war needs during the war itself.
The relevant Wikipedia article reads:
The Allies were to send 300 tons of provisions on a daily basis. According to the Romanian account, most of these clauses, with the exception of those imposed on Romania, failed to be respected.
The promise itself seems implausible, given that the Allies were unable to supply Russia, except in a trivial way. The World War II Persian Gulf route, had not been built, a small road from Murmansk on the White Sea to points further south was built only during the war, and the Siberian railroad was problematic. The most obvious supply route, through the "Straits," was controlled by the Central Powers (Turkey).
So what made the Romanians believe that the Entente could supply them adequately? Was it because their needs were so far below Russia's that "trivial" for Russia would be "adequate" for them?
Germany's General von Hindenberg hinted at as much by opining:
It is certain that so relatively small a state as Rumania had never before been given a role so important, and, indeed, so decisive for the history of the world at so favorable a moment. Never before had two great Powers like Germany and Austria found themselves so much at the mercy of the military resources of a country which had scarcely one twentieth of the population of the two great states. Judging by the military situation, it was to be expected that Rumania had only to advance where she wished to decide the world war in favor of those Powers which had been hurling themselves at us in vain for years. Thus everything seemed to depend on whether Rumania was ready to make any sort of use of her momentary advantage.