I've figured out what the hard-line pro-war America-rah-rah-rah mood of this country reminds me of. Ironically enough, it's France.
In 1792 and 1793, respectively, France declared itself a republic and executed Louis XVI. It was, in popular imagination, the most democratic act in the history of the world; France was committed to liberty and the will of the people in a way that no other nation was. The mood of the country, and especially of the dominant faction in its government, was strongly patriotic. France, after all, was showing the rest of the world how a country should be run.
The new republic was also highly paranoid; it feared that hostile emigres were plotting to sow disorder in France and overthrow the new government. In 1792 and 1793, France declared war on Prussia, Austria, Russia, England, Spain, and various minor German principalities; it invaded Belgium, the Netherlands, Savoy, and Avignon.
French armies entered these newly-conquered territories with promises of liberation from tyranical monarchs and almost immediately instituted elections whose expected outcomes were made quite clear. France was engaged on a grand project of remaking Europe in its own image, replacing kings and emperors with citizens and assemblies.
History had other ideas. In the face of near-universal opposition from the other world powers, a few notable defeats on the battlefield, and a severe economic crisis, the French turned on themselves with a vengeance. In the Terror of 1793 and 1794, the ruling Jacobins used the machinery of government to suppress dissent and execute their enemies. Even after their fall, France's troubles were hardly over--it spent most of the next two decades at war, three-quarters of that under the control of a military dictator.
It's all highly sobering.