Describe Donald Rumsfeld's career in government as noted in the nonfiction book, The Afghanistan Papers?

Rumsfeld’s career in government is quite extensive. He was elected to Congress at the age of thirty, where he served as a Congressman from Illinois, his home state, from 1963 to 1969. He resigned from Congress mid-term to serve in the Nixon administration’s cabinet. Under Nixon he was appointed Director of the Office of Economic Opportunity and eventually was dispatched to Brussels to serve as the US ambassador to NATO. During his time in the Nixon administration he cultivated close ties with future Deputy Director of the CIA Frank Carlucci, and future Vice President Dick Cheney. Carlucci would become a notorious of the agency’s extra-legal measures that often led to mass violence in the decolonizing countries of the world. Dick Cheney, would go on to become, with Rumsfeld himself, one of the architects of the Iraq War. After Nixon’s resignation following Watergate, Rumsfeld was appointed President Gerald Ford’s Chief of Staff before eventually becoming Secretary of Defense.