For Berlinguer, the events in Chile proved that the Marxist left could not aspire to govern in democratic countries without establishing alliances with more moderate forces.
[1][2][3] Another major reason for the change in PCI policy was the advent of the 1973 oil crisis that challenged the Western welfare states and would ultimately provide the pretext for neoliberalism.
Stephen Gundle has remarked that the party had legitimate reasons to fear a resurgence of fascist authoritarianism due to the terrorist strategy of tension employed during the Years of Lead, along with the increasing electoral strength of both the centre-right and far-right.
"[11][12] However, Lucio Magri also notes that Berlinguer "enjoyed unlimited trust" in the ranks of his party, and was not rebuked when he moved to the right on such sensitive topics as Italian NATO membership.
[13] Finally, in the aftermath of the 1976 election, the PCI started to provide external support to a Christian Democratic one-party government led by Andreotti.
This minority government – the DC had achieved a score of 38,8% – derived its legitimacy simply from the promise of the PCI and PSI to refrain from declaring no confidence in it.