For socialists, Europe was both an area for political practices as well as an ideological horizon. The road of exile and international congresses made the continent into a lived space. This territory was later conceived of as a political place, however European integration deeply divided socialists, even if a number of their leaders were prominent figures in the construction of Europe. Parties from the north were especially reluctant to join the community, seen as being too neo-liberal.
Source : Socialists and Europe