203. Is war a mandatory duty even with less strength of force?

This verse of the Quran 9:41 says it is mandatory to wage a war even if with less strength on one’s side. 

But verse 8:66 of the Quran says a war is mandatory only when the strength of the enemy is half of the other side, making it look like self contradictory

In verse 8:66 of the Quran Allah says ‘ Allah has made it easier for you now, and then goes on to mention the required strength to wage a war.Hence it can be known the initial stance has been changed

The responsibility of protecting the subjects rests with the rulers, only venturing into the battlefield to save the people from invaders would protect the people. But at times when the strength of the enemy is high, it would spell disaster.

At such times it is wiser on the part of the rulers to selectively ,by their decesion protect the subjects as it suits them,.Allah makes it clear in these verses the ways and means to protect people by their rulers.

We come to understand war is mandatory from theses verses, only when the strength of the enemies is half of the other side, and when conditions and requirements are not good enough for a war better to avoid one and save the people from its ill effects.Please refer to points 53, 54, 55, 76, 89, 197, 198, 199, 359 to know more about war, terrorism, JIhad etc