On 14 May 1955, the USSR and other seven European countries "reaffirming their desire for the establishment of a system of European collective security based on the participation of all European states irrespective of their social and political systems" established the Warsaw Pact in response to the integration of the Federal Republic of Germany into NATO, declaring that: "a remilitarized Western Germany and the integration of the latter in the North-Atlantic bloc [...] increase the danger of another war and constitutes a threat to the national security of the peaceable states; [...] in these circumstances the peaceable European states must take the necessary measures to safeguard their security".

In which month of 1955 was this pact declared?