Really, all wars are about ideas.

Both sides try to convince the other that it's pointless or not worthwhile to keep risking your life for the ideas you're fighting for. Those ideas usually involve the widely held worldview of the each side -- who should rule, and how. Both winning and losing will profoundly influence ideas of who was right and wrong and why.

The U.S. Revolution was primarily fought over the idea of Independence. The U.S. Civil War was fought over the idea of preserving the union versus the right of self-determination.

Power, and my right to use it, is an idea many have fought and died for.

Most World War II victors -- Communists, Western Democracies and monarchies -- believed their collective ideas had triumphed over the twin ideas of fascism and militant royal imperialism. Many important battles took place in the arena of ideas.

The 30 Years War involved interpretations of religion and how they would affect political power.

The Arabic/Muslim conquests after the death of the Prophet were so successful because they were accompanied by religious ideas that a billion people continue to find compelling.

Turn the question on its head. Has any successful military compaign been devoid of ideas? Has any successful, long-lasting victory taken place in the absence of convincing the population that the victorious power deserves to rule?