Friction is the term used by Carl von Clausewitz in On War (Book 1, chapter 7) for example "activity in war is movement in a resistant medium"
It can be found here https://www.clausewitz.com/readings/OnWar1873/TOC.htm#a
He also noted that once a war is undertaken whatever the end, the only means is to fight – and each side competes to harm the others ability to do so - war is therefore not a very flexible tool for achieving a political objective by other means