History shows that there are no invincible armies, and never have been. napoleon's army was considered invincible, but was beaten successively by russian, english and german armies. kaiser wilhelms german army in the period of the first imperialist war was also considered invinsible, but was beaten several times times by russian and anglo-french troops, and was finally smashed by the anglo-french forces.
which statement is the most reasonable inference about one of the underlying meanings of this excerpt?