War is an inherently political instrument used to achieve a political objective, so a credible political adversary is necessary for war to be war.
As the US Presidential election race hots up (or gets more one-sided, depending upon your interpretation), people continue to refer to former President George W Bush leading the US into two “wars” in Iraq and Afghanistan. Thinking about it, I’m not sure the two can actually be classified as wars.
To use a chess analogy, real wars seldom end in checkmate – they most often end in resignation or an agreed draw. War is an instrument that is used to achieve a political objective, to get the other party to do what you want them to do.
And so war ends when one side has established such an utter dominance over the other that the counterparty decides that to resign, or “surrender” is superior to continue fighting the war.
For this to happen, however, the counterparty needs to have political leadership that is able and willing to make a decision, following which the war actually stops. In the absence of such a political leadership, the war will continue indefinitely until “checkmate”, and assuming that the losing side’s force “decays exponentially”, it can take a really long time for it to actually get over.
So based on this definition that war is a political instrument used to achieve a political objective, I’m not sure what happened in Iraq and Afghanistan can actually be classified as “war”.
The “government” of the day in Afghanistan (Taliban), for example, would have never come to the negotiating table with the US, so short of complete annihilation, there was no other “objective” that the US could achieve there.
Iraq, on the other hand, possessed credible political leadership (Saddam Hussein) when the US invaded, but by actually killing him, the US denied themselves the chance of a “real victory” in terms of a negotiated settlement. A game of chess might end when the king is mated (remember that the king never “dies”, only trapped), but in a situation such as Iraq, the battle will rage until each member of the opposing force is taken out.
And so fighting continues to this day, over a decade since it started, with no hope of it ending in the near future. Real wars never go on indefinitely.