Argentina–Spain relations were made declassified and stated that Prime Minister Margaret Thatcher feared that during the Falkland war, Spain would join Argentina by invading Gibraltar. A dispute arose in 2012, when Argentina sought to nationalize the energy company YPF, owned by the Spanish multinational company Repsol. Spain warned against such a move stating that it would harm bilateral relations if such a move were to happen. On 16 April, Argentina's President Cristina Fernández de Kirchner announced the nationalization of YPF, to which Spain warned of a "clear and decisive" response. Since then, Argentina has recompensed the Spanish government and Repsol over the
Repsol of the massive Vaca Muerta shale-gas field. The board of the Repsol firm unanimously rejected this offer, as it would have caused them to drop a $10.5 billion lawsuit that was in progress against the Argentine government. Repsol at the time owned 6.4% of the YPF oil-and-gas company. On 25 February 2014 the Repsol board announced it had accepted a settlement offer from the Argentine government of an issue of Argentine bonds valued at $5 billion. The deal concluded after 3 months of negotiations in Buenos Aires was subject to shareholder approval. The agreement ended two years of legal wrangling