Which is better pandemic or war?

Neither        

It's impossible to say without including scale.  Not all pandemics are deadly, and some wars are much worse than others.  Like so many things it's not about this or that but rather how much of this or that.  

Both kills people. That is why we need God's Kingdom. It will eliminate all causes of disease, suffering, wars, crimes, poverty, etc. (Psalms 37:10,11; Psalms 46:9;Micah 4:4; Revelation 21:4)

Pandemics are awesome!

Wars suck ***. 

War without a doubt. Nothing wrong with that. At least you have an option not to be in it. Unlike the virus you don't know where it is most of the time and can get it even when still being clean along with also doing as mandatory.

War is human error.

A pandemic tends to be containable, even if there is unusual, lab-added gain-of-function.

One precedes the other...

N.Shadows

A Pyrrhic choice.

War kills and displaces people, and destroys infrastructure.  A pandemic only kills people, and if people take precautions, it should not even do that.

Pandemic is better then war.