One of the things that makes people reluctant to compare the standoff with Iran over nuclear weapons and Germany's occupation of the Rhine is that Germany was such a powerful nation, with deep reserves of scientific talent and economic resources. Iran, even with its oil reserves, is an economic basket case.
But the very fact of Iran's weakness makes its acquisition of nuclear weapons even more dangerous. They have nothing to lose from confrontation and little to gain from peaceful intercourse with the world. Notice that Russia was all along a weak nation but was at the center of world affairs becuase of its armament AND becuase of its anemic economy.