Through his career spanning over 50 years, he reported from many countries including the former Soviet Union, China, the United States, and Afghanistan.

He was the first German journalist with a visa to work in Yugoslavia, and the first correspondent for national television ARD in Moscow.

Ruge summarised his reports in books such as Sibirisches Tagebuch ("Siberia Diary") and Russland: Portrait eines Nachbarn ("Russia: Portrait of a Neighbour") and Unterwegs: politische Erinnerungen ("On the way: political memories") Ruge co-founded the German chapter of Amnesty International in 1961.

[7] In 1968, Ruge was in the United States, and reported after the assassination of American senator Robert F. Kennedy whom he had known personally.

[9] In this period, some of his articles on Chinese foreign policies in the context of the cold war between the United States and the Soviet Union were published in The New York Times.

He was close to the Soviet leader Mikhail Gorbachev, who had called him a person of high moral values.

[6] During the Soviet coup d'état attempt in August 1991, he reported for over 72 hours broadcasting the resistance which saw Gorbachev holding on against the uprising from opponents of his reforms.

[14] Along with fellow journalists Felix Rexhausen and Carola Stern, Ruge founded the German chapter of Amnesty International in Cologne in 1961.

[20] His travel reports from multiple places including the Russian countryside, the civil rights movement from the United States, or from a traffic-jam in Moscow, were noted to have authentically captured the mood of the people on the ground.

He was known to start his travel reports with the locals with a simple question seeking "Und, wie ist das Leben?"

[12] Ruge was awarded the Otto Hahn Peace Medal in 1999 and the Commander's Cross of the Order of Merit of the Federal Republic of Germany in 2014, among others.