azzaman333
meh
Get the BUG mod. It shows you your power ranking.
Based on the use of the mod and this ranking I can tell you definately that war comes to you when your military is weak. The mod shows you a ratio of your strength (units, buildings, etc) against theirs. When this ratio hits .5 you will be attacked by those not of your religion. Lower than that and even those of your religion will attack you.
Plain and simple fact, but you have to have the mod to be able to see it happening.
That's merely coincidental. Power only affects a small part of the war decision, which I have outlined above.