The 19th century German writer Ludwig von Rochau wrote that the first step towards understanding leads to the conclusion that the law of the strong over political life performs a function similar to the law of gravity over the material world. Those words were part of his explanation of realpolitik, which is the practical use of power as well as material considerations and factors in diplomacy and politics.
Realpolitik is a theory of politics that focuses on power rather than morals, ideals and principles. The term is often associated with 19th century nationalism and it was used to describe realistic politics instead of overzealous or unrealistic politics. The Revolution of 1848 actually created realpolitik to strengthen states and tighten social order. Otto Von Bismarck was the first Chancellor to get behind the concept we think of today as realpolitik. He used it to gain Prussian dominance over Germany in the 19th century.
Bismarck used Machiavellian policies, which demonstrated a pragmatic view of the real political world. He supported liberal social policies like employee insurance, which gave him the ability to manipulate change from the top rather than face major changes from the bottom up. Another strategic realpolitik move was not accepting territory from Austria after the Prussian's defeated that country in the 19th century. That move was the catalyst for the unification of Germany.
Henry Kissinger introduced realpolitik to the Nixon White House. He advocated realpolitik policy by dealing with other powerful nations in a practical manner rather than basing a relationship on ethics or political doctrine. The best example of that strategy was Nixon's visit to the People's Republic of China. Most US citizens and Congress opposed communism. Most of the US supported a doctrine of containment so the visit was a bold move and a great realpolitik strategy.
Another example of Kissinger's realpolitik came in 1973 after the Arab-Israeli War. Kissinger persuaded the Israelis to partially withdraw from the Sinai even though there were political issues pending from the oil crisis.
Realpolitik is related to the philosophy of political realism, which is rooted in the pursuit, application and possession of power. Kissinger, one of the henchmen of the New World Order, invented the term to put an academic face on the exploitative and brutal practices of the modern state.