The Age of War is over. All the land has been "discovered". It's all been divided up and international law pretty much forbids anyone from taking anyone else's land. Israel is the holdout on this one.
We have the technology to destroy the planet in a matter of hours.
Whatever the question may be..."War" is the wrong answer.
The Age of War has yet to arrive. It will come with the climate trying to kill us through world wide Famine, Disease, Thirst, break down of society, failure of Rule of Law and the institution of Us Over Them. In short; the arrival of the Four Horsemen and their cousins and lesser siblings.
Fully agree with your last statement, but we will never have the chance if we do not do something now.