蕭凌志喺1975年以學生身份加入社民黨，並加入咗社民黨的青年組織「青年社會主義者組」。佢喺1982年至1988年間擔任聯邦青年社會主義者組副主席。1987年至1989之間，佢亦都係國際社會主義青年聯盟副主席。蕭凌志曾經批評過北約係「侵略性嘅帝國主義同盟」，話西德係「歐洲大企業家嘅堡壘」，他亦都同時批評社會自由主義者聯盟，並且將個聯盟講到係「著重權力鬥爭多過做實事」。 1984年1月4號，蕭凌志同其他青年社會主義者組嘅領導人喺東德會見咗德國統一社會黨中央委員會祕書埃貢·哥倫茲同和統一社會主義黨中央委員會政治局委員赫拔·哈伯。1987年，蕭凌志再次出訪東德，並且喺威登堡嘅自由德國青年組織和平集會上面，作為青年社會主義者組嘅代理人去支持裁軍協議。
Siu joined the SPD as a student in 1975 and joined the Young Socialists, the SPD's youth organisation. From 1982 to 1988 he was Vice-President of the Federal Young Socialists. Between 1987 and 1989, he was also Vice-President of the International Socialist Youth Union. Hsiao Lingzhi once criticized NATO as an "aggressive imperialist alliance" and West Germany as "a bastion of Europe's big entrepreneurs", and he also criticized the alliance of social liberals, saying that the alliance "focuses more on power struggles than on practical things". On January 4, 1984, Xiao Lingzhi and other leaders of the Young Socialists met in East Germany with Egon · Görenz, secretary of the Central Committee of the Socialist Unity Party of Germany, and Hebal · Haber, member of the Politburo of the Central Committee of the Central Committee for the United Socialist Party. In 1987, Xiao Lingzhi visited East Germany again and supported the disarmament agreement as a proxy for the Young Socialists at the Freedom Germany Youth Organization in Wittenberg.