Complex sentence: Macmillan, obsessed with economic expansion, constantly belittled Lloyd in his memoirs, and in Mount's view just as Suez was in foreign policy, so Macmillan's sacking of Lloyd was a watershed in economic policy, opening the way to the inflation of the 1970s.
Split into simpler sentences: Macmillan, obsessed with economic expansion, constantly belittled Lloyd in his memoirs. In Mount's view, just as Suez was a watershed in foreign policy, so Macmillan's sacking of Lloyd was a watershed in economic policy, opening the way to the inflation of the 1970s.