Victor Davis Hanson answers the question why certain wars never end:
Weaker enemies, by design, do not threaten stronger powers existentially; ‘proportionality’ means stalemate.
From the Punic Wars (264–146 b.c.) and the Hundred Years War (1337–1453) to the Arab–Israeli wars (1947–) and the so-called War on Terror (2001–), some wars never seem to end.
The dilemma is raised frequently given America’s long wars (Vietnam 1955–75) that either ended badly (Iraq 2003–11) or in some ways never quite ended at all (Korea 1950–53 and 2017–?; Afghanistan 2001–).
So what prevents strategic resolution? Among many reasons, two throughout history stand out.
One, such bella interrupta involve belligerents who are roughly equally matched. Neither side had enough of a material or spiritual edge (or sometimes the desire) to defeat, humiliate, and dictate terms to the beaten enemy. Think Rome and Carthage from 264 to 146. For 118 years, they fought three Punic Wars until greater Roman growth and vitality finally allowed it to dominate the Mediterranean and dictate terms on the North African coast, which finally resulted in the destruction of the Carthaginian Empire rather than another defeat of it. There was no fourth Punic War.
Certainly over the length of the Hundred Years’ War, England and France were often either too equally matched, or both lacked the necessary military clout to destroy their adversary’s army, march on the respective enemy capital, occupy it, and end both the material and political ability of the losing side to make war.
In contrast, there was not another American Civil War, because after the invasions of Grant, Sherman, and Sheridan between 1864 and 1865, the Confederacy lost the ability to resist, and Union armies forced an unconditional surrender and a mandated reentry into the Union. The same sort of resolution was true of the Second World War, in which the victorious Allies agreed that they should and could destroy the political regimes — at whatever cost — of Germany, Italy, and Japan. The combined manpower, GDP, and munitions of Britain, the USSR, and the United States allowed them to crush the Axis — once they had the willingness to pay a high price in blood and treasure to avoid a World War I–like armistice that they believed would have led to World War III.
Read more: National Review