I read today that the US government is spending $20 billion per year on air conditioning in Afghanistan. $20 billion!! (That deserves an extra exclamation point).
No wonder the bad guys--whoever they might be--are preventing the US military from "winning", however politicians want to define that. They don't have air-conditioned caves, dugouts, or hovels; they don't need luxuries to fight a war.
No combat is fun or easy. Afghan fighters are defending tribal territory, perhaps with some help; US soldiers want a soft life and all the amenities of home.
I seem to recall that the US were defeated and humbled by little Asian men in black pajamas and tire-soled sandals, who survived on a handful of rice and wet spot in a tunnel. Only the Air Force and headquarters had air-conditioning, but the rest of us had plenty of comforts and ate rather well. Americans take "home" with them to war; the other guys survive on what they are used to...which is considerably less.
Of course, no American soldier would put up with local conditions, so the government would be unable to wage these unpopular wars. Fortunately for them, no politician would dare to suggest cutting military spending.
I thought of Vietnam as a comfortable war, but it seems that life at the front has improved...