I always knew it mattered from my long term study of the Wars of the Three Kingdoms but beginning to look at the Thirty Years' War more recently really bought it home to me- there was no more destructive conflict until the outbreak of WW1 which gives one pause for thought.

If it really didn't matter, why was most of central Europe reduced to a disease ridden, starving bloodbath for thirty years in the early to mid 17th century?