A survivor of the November 1938 Kristallnacht pogrom in Berlin, he was a senior campaigner for human rights, prominently involved in public acts against the distribution of weapons of mass destruction in the Middle East.
About half a year later, in March 1939, he was joined by his photographer wife, Grete Lina Spiro, and their two children, Gideon and his younger brother John Gabriel.
Gideon was a graduate of the Hashomer Hatzair youth movement and the network of informal relations between teachers and students that he observed at a summer work camp on a kibbutz made a profound impression on him.
He returned for a short while to Europe on a journalistic assignment, and wrote from Czechoslovakia where he had travelled on a visa that he had received before the breaking of relations between the Eastern Bloc states and Israel.
The IDF’s occupation of the West Bank and Gaza Strip in 1967 caused Spiro to question his Zionist outlook, and while in America he was impressed and influenced by the activities of the protest movement of American youth against the Vietnam War, including actions such as the burning of draft cards, the slogan “Hell no, we won’t go!” and the October 1967 “March on the Pentagon” at which tens of thousands of demonstrators surrounded the Pentagon, facing armed soldiers.
During those years Spiro was a member of a group that wanted to found a Hebrew magazine along the lines of and under the inspiration of Der Spiegel, where he was a guest journalist for a few months.
He was one of the founders of the Yesh bloc, a federation of left-wing student groups - encompassing kibbutzniks, Mizrahim and South Americans - who were joined by Arab students led by Adel Manna (later a prominent historian and the director of the Centre for the Study of Arab Society in Israel at the Van Leer Institute in Jerusalem) and Issam Makhoul (later a Member of the Knesset and the General Secretary of the Israeli Communist Party).
Spiro was elected editor of the student newspaper, which he replaced with a new publication called Post-Mortem, which dealt with social, economic and political matters and which published several scoops and exposés about the university.
The newspaper’s subversive character, Spiro’s regular columns in it and the fact that Arab students were invited to contribute to it on an equal basis upset the rector of the university, Benjamin Akzin, and subsequently the political establishment in Jerusalem as well, headed by Golda Meir.
Spiro drafted the outlines of the Yesh platform, which included explicit opposition to the Israeli occupation of the West Bank and Gaza Strip, Sinai and the Golan Heights.
On the occasion of the national students’ strike of 1972 he coined the slogan “Transfer the billions from the Territories and corruption to education, housing and raising the living standard of the marginalized”.
Before that he also managed to stay for ten days as a correspondent for the left-wing weekly HaOlam HaZeh on board Abie Nathan’s “peace boat” on its way to Port Said on the second anniversary of the 1973 Yom Kippur War, with the objective of giving 100,000 flowers to the Egyptian people.
He published strongly worded letters and articles in which he expressed harsh criticism of Begin, Sharon and Eitan – the latter two being former commanders of his from his army days – and called for the three of them to be put on trial for war crimes.
In January 1989 he was questioned by the police after he distributed to soldiers enlisting in the army the alternative “service booklet”, with Yesh Gvul, to convince them to refuse to serve in the Occupied Territories.
In July of that year the weekend supplement in Haaretz ran a long interview Spiro conducted with Hilde Schramm, daughter of former Nazi architect and Minister Albert Speer.
Between 1989 and 1992 he also worked for the German-Jewish monthly Semit, for which among other things he did an interview with Prof. Yeshayahu Leibowitz, and in 1994, at the time of the Oslo Accords, he wrote for Yom Le-Yom, the newspaper of the Shas Party.
He has participated and lectured in many international gatherings on behalf of the "Israeli Committee for a Middle East Free from Atomic, Biological and Chemical Weapons", and was one of the few main consistent supporters of Mordechai Vanunu.
Spiro was convinced that the trial of the five Israeli Arab defendants was defective due to a bias caused by two factors: the intense public pressure that was applied on the court, and the fact that the judges were not independent of the political system and the “occupation establishment”.