Well, it gives Congress authority to pass any laws that are "necessary and proper" to carrying out any of the governments expressed powers. Such as levying taxes, declaring war etc. So for any issue that the Framers of the Constitution couldn't predict, Congress can pass a law that allows them to carry out their enumerated powers.
1)he formed the good neighbor policy with latin america 2)he led america through the great depression and WWll 3) he assisted china in their war against japan
