Realpolitik

Realpolitik is a system of politics or principles based on practical, rather than moral or ideological considerations. Realpolitik is the idea that the world is ruthless and you have to act realistically, even if it causes other things to happen that are bad, or decisions have to be made that upset your people.
Ludwig von Rochau was a 19th century writer and politician. He describes it as follows: 
A good example of a realpolitik politician is Henry Kissinger, who helped U.S. Presidents in the 1960s and 1970s to expand the power of the United States and its allies.