No I think your wrong, most countries multi secular.
Not delving too deep into the reasons but If I recall, WW1 started because the killing of Arch Duke Ferdiand, WW2 Herr Hitler wanted some of their old dirt back and because inflation was out of control, so why not blame everyone who is not their shade of white, Tojo joined in thinking it could knock off a few countries to get natural resources.
Korea and Vietnam was to stop the spread of the commies, more recent wars have been religious because of how you read this book is different to how I read it, or its just tribe against tribe, the wars in Europe started with the break up of the USSR even today Russia wants to reunify a lot of the countries that departed of the break up.