Are democracies inherently flawed when it comes to running a war? Does a strong executive (to use the modern terminology) make the running of a war more efficient, if not always more successful?
Thucydides would say so, and indeed he lays the blame for Athenian defeat mostly at the hands on the demagogues, who were non-aristocrats who became leaders. Lincoln and Roosevelt would also say so, and both took extraordinary steps to suspend basic liberties in light of wars, intending to relinquish their hold once the crisis passed. Romans would agree, having two consuls run the war efforts, but when times became most critical they nominated a dictator to take over all power for six months and completely direct the war effort. Napoleon would agree, Han Solo would agree, and every president since Vietnam would agree, the list goes on.
The virtue of having a sole, or very small group of leaders does not guarantee success in a war, and in some instances the virtue of having one person in command of the overall strategy could guarantee defeat, but there is not the fickle aspect of democracy and there is a time when one person needs to step to the fore and expedite the process.