The Russian Democratic Federative Republic
Founded around mid-day and dissolved before bedtime on Jan. 19, 1918, the Russian Democratic Federative Republic must hold the record for the briefest country in history. Mind you, its brevity is understandable considering the circumstances. The previous year had seen not just one but two violent revolutions shake the Russian Empire to its core.
Multiple factions from the right, left and center were fighting tooth and nail for power. In January 1918, a democratically elected Russian Constituent Assembly declared the establishment of a Russian Democratic Federative Republic. But an executive committee controlled by the Bolsheviks felt the core ideas of the new republic were too moderate and would not spark the necessary socialist reforms, at least not at the speed required by the radical left.
The executive committee promptly dissolved the nascent republic, and the chief Bolshevik himself, Vladimir Lenin, rose and delivered a two-hour address explaining how bourgeois the assembly was. Another country was in the offing, and this time it would last a little longer [source: Bunyan and Fisher]. That country, of course, was the USSR.