During World War II Aarons was rejected for military service on security grounds, instead serving in the CPA's bureau for party members in the armed forces.

The period during and after World War II saw the CPA at the peak of its strength and influence, with about 10,000 members, under the veteran party leader Lance Sharkey, who had been installed by the Comintern in 1930.

In 1969, at meeting of world Communist parties in Moscow, he made a speech strongly critical of the invasion and of Soviet policy under Leonid Brezhnev generally.

During the 1970s the CPA became a strong supporter of "Eurocommunism", abandoned Leninism and democratic centralism, and tried to form a "united front" of the various left-wing forces thrown up by the movement of opposition to the Vietnam War.

During his declining years in the town of Maianbar, New South Wales, despite several painful medical conditions, Aarons continued to involve himself in community activities and to write books and articles.