necessary
Everything in the past, including war was necessary, because it existed. This does not mean to say that it is necessary now or in the future.
Example:
People started to realize the basic game center could move to life support instead of death support and it was now necessary to work for only 6 hours per year instead of the current 2,000, to support war mongers.
People started to realize the basic game center could move to life support instead of death support and it was now necessary to work for only 6 hours per year instead of the current 2,000, to support war mongers.