How did the Slaughterhouse Cases and United States v. Cruikshank affect the scope of the Fourteenth Amendment?

It allowed state legislatures to suspend blacks' legal and civil rights as outlined in the Constitution. The Court ruled that only states, not the U.S. government, had the right to prosecute Klansmen under the law.

Diplomacy can be used because diplomats create treaties and agreements on problems and these treaties resolve problems in such a way that it benefits both sides. If it doesn't benefit both sides, then it's usually as a result of a war effort. Good diplomats for example like Henry Kissinger can completely turn the way a politician behaves, like he opened China a bit to the west even though it was believed to be impossible.