For Tierno and his collaborators, the strategy of creating a network of international contacts in the academic field was a choice and a necessity. The causes are different. First, it was a matter of contingency and availability: Tierno's role as a scholar and intellectual made this type of contact available. Secondly, the University, although it was structurally linked to the Regime, was not monolithic. Government control used to leave wide margins for action, out of respect for the status of a professor and due to the disinterest of the authorities. This distance, for example, allowed the “survival” of the Boletín. Furthermore, the role of intellectual allowed Tierno an international circulation of ideas which was very infrequent during Francoism. Therefore, this guaranteed him - who was often under the eye of the authorities - a "cover" for his philosophical-political communications, directing him towards a certain class of interlocutors and shaping his network of contacts.
The first contacts of this kind date back to 1943, when Tierno met José Antonio Maravall and Carlos Ollero at the Ministerio de Educación Nacional . Both were crucial to his inclusion in the academic context. The first assignment in Murcia was characterized by the total absence of politics from his acquaintances, except for Carl Schmitt, who believed that Tierno was "the most promising Spanish intellectual".
The turning point came with the young intellectual's transfer to Salamanca, a city in full cultural ferment. This endowed Tierno with the courage necessary to deal with unorthodox themes in his seminar, attracting a series of collaborators from different political and social backgrounds: the "grupo de Salamanca". It is worth mentioning Raúl Morodo, Tierno's future right-hand man. Some of the other notable names, including those from other universities, were Elías Díaz, Federico Chiriboga, Jorge Enjuto, Pedro de Vega and Fermín solana, and Professor Pablo Lucas Verdú. Furthermore, in the César Carlos residence, Raúl Morodo also began to collaborate with other students: in particular Emilio Cassinello, destined to be among the most active international leaders of the party. Among other personalities, it is worth mentioning the European federalists Manuel Medina and Gumersindo Trujillo. In the same years, Morodo also became friends with the exiled pro-European leader Enrique “Gironella”.
The “grupo de Salamanca” launched a cultural resistance project, the Boletín. Then they created the AUFE, a political association that caused prison and judgement to Tierno and other members. The most relevant elements in this episode were the international media exposure of Enrique Tierno, and the withdrawal of the passports: Tierno and Morodo were not allowed to leave the country, even to participate in academic events. The group, over time, was enriched with new members: one of them was Fernando Morán. This enlarged nucleus was the basis for the establishment of the subsequent political organizations founded by Tierno.
During the Salamanca years, Tierno also made important contacts with other professors. Their most important legacy was the inclusion of Tierno in the academic circle of the tolerated opposition to Francoism. In turn, this led to new contacts. For example, the friendship-rivalry with Joaquín Ruiz-Jiménez facilitated Tierno's inclusion in Christian Democratic circles. Similarly, the scholar Argumosa, whom he met at university, introduced him to the liberal monarchist Joaquín Satrústegui, leader of Unión Española.
At the end of the 1950s, when the Salamanca era ended, the Tierno group continued to work together. A phase of new university contacts began, especially through the new academic experiences of Tierno and Morodo. Morodo also became a disciple of Carlos Ollero, together with old friends Díaz and de Vega and new contacts: among them was Miguel Martínez Cuadrado, future point of reference in relations with the European federalists. All of them collaborated in the Instituto de Estudios Políticos. Likewise, Morodo organized a democratic student movement together with Javier Pradera, Díaz and Ramón Tamames.
In the same years, Tierno established his first contacts with the socialist opposition inside and outside the Country. He also began to increase his links in foreign universities. His "exile" led him to take a course at Princeton University. In those years, in fact, Tierno's relationship with the United States of America (USA) was promising, as he had been reported to the Council of Foreign Relations by Professor Arthur Whitaker. In the following years, the “viejo profesor” would often travel to American universities. Thanks to Morodo, he met the Spanish exile Victoria Kent: both collaborated a lot with the important magazine edited by her, "Ibérica". This allowed them to strengthen contacts with Spanish dissident intellectuals living in the USA.
Furthermore, in the context of the magazine they both collaborated with the young Portuguese socialist leader Mario Soares. He had met Morodo in 1965 in a judicial investigation, and will be a very important contact for the Tierno group. A friend of Morodo, Soares actively helped their political party in its relations with the SI, the Social Democratic Party of Germany (SPD) and the PSOE. In any case, the Tierno group's relationship with the USA continued for many years: some decisive events were the letter from the anti-Franco opposition to Secretary of State William Rogers (1970), Raúl Morodo's trip to the USA at the invitation of the State Department (1973), and the failed negotiations for US recognition of the PSP (1976).
Tierno extended his “exile” in the University of Puerto Rico. Morodo also gave a course at this university (1963): his passport was returned to him thanks to the help of Pío Cabanillas, known among Madrid's academic circles. It was the beginning of the American academic adventures for Tierno's young aide, during which he significantly enriched his political network among exiles in South America, Mexico and the USA: among others, Jiménez de Asúa, Jorge Enjuto, Victoria Kent and José Bullejos. He also met various Mexican government figures, such as Echevarría and López Mateos.
In 1965, Morodo was invited to the Universidad de Santiago de Chile through Francisco Ayala. The contacts made in many Latin American countries - especially in Mexico and Venezuela - will have a fundamental importance in the ideological orientation and financing of the PSP. However, in Chile Morodo also came to participate in the activities of the Socialist Party and become friends with Salvador Allende. In the autumn of that year and during the same stay, he met Robert Lamberg, thanks to Professor Jorge Barría. The following year, Lamberg will be the person appointed by the Friedrich Ebert Foundation (FES) - an offshoot of the SPD - to delve into the situation of Spanish socialism and choose political partners to support. His evaluation will be positive especially towards the Tierno group: this made the financing of the FES possible for them too, despite the reticence of some elements of the SPD. This funding will be of vital importance to the PSI and PSP, and its loss will be an important indirect cause of the party's electoral defeat. Likewise, German support guaranteed credibility in the eyes of the SI; but when this went down, it leaded to the victory of the PSOE of González.
The first contacts between the SPD and Tierno had actually a political nature: he was the person in charge of the PSOE to receive Fritz Erler in Madrid in the winter of 1965. Yet, it must be underlined that the "viejo profesor" presented himself more as an intellectual than a political leader. Furthermore, the collaboration between FES and PSI/PSP often had an academic basis, relying mainly on the awarding of scholarships in Germany and on seminars. Tierno's main proposal, in 1966, was to cover the political activities of the FES and the Tierno group through the creation of a study center in Madrid. The cultural soft power tricks used by the Tierno group should also be underlined: for example, in 1968, to re-establish relations with the FES, the foundation was offered the publication of the books of the exponents of the SPD and the FES in Latin America by Tecnos publishing house, related to the group.
Once the PSI was created (1968), the academic factor continued to be important for two reasons: it provided contact with other political circles, and it served as an expedient for the leader's international circulation. For example, Tierno was invited to Italy in 1969 by the Istituto di Studi Europei as an intellectual. This trip gave him many allies among the Italian pro-Europeans and socialists: contact with them had occurred thanks to José Luis Daneo, a former student of Tierno residing in Italy. These contacts led to the creation of the Spanish Section of the European Federalist Movement, whose president was the "viejo profesor". Another relevant case was Tierno's trip to England in May 1975, in which he had the opportunity to make contacts with the Labor Party and to be interviewed by the BBC. Also on that occasion the invitation came from the academic field. Furthermore, the trip was made possible by old student Fernando Morán, who worked in the Embassy with Manuel Fraga.