This is absolutely correct and I think the same thing whenever I read suggestions that Roman defeats are/were significant to its decline. Rome's major strength

This is absolutely correct and I think the same thing whenever I read suggestions that Roman defeats are/were significant to its decline. Rome's major strength from the beginning was an indefatigable political will. Hannibal did not just cross the Alps, he decimated multiple Roman armies in Italy and then rampaged around the peninsula for over a decade. There is an anecdote that when Hannibal's armies approached Rome, inside the city Roman traders sold land rights to the spot on which his army camped. Much like the Russians and Americans have found in Afghanistan, it is hard to defeat an enemy that shares a common fundamental belief in its own persistence and refusal to acquiesce. Even in this story, as the article notes, after having lost three legions in an utterly decisive battle in the wilds of Germania, Emperor Tiberius' son Germanicus decided he would go back and wage more war to recover the standards. That is not the sort of political will we are used to.