Between 1971 and 1974, de Cruz was a columnist for the New Nation, of which he was also Diplomatic Editor. His columns and occasional editorials, whether on international or domestic affairs, are marked by a combative humanism that takes on a range of issues from communism and race to sex and juvenile delinquency. Invariably trenchant, often wry and irreverent, sometimes controversial, occasionally contentious and at times spoiling for an intellectual fight, his writings revel in the columnist's art — to provoke the reader to some purpose. His favourite enemies are ignorance and hypocrisy in society. Cant and humbug passing off for tradition and orthodoxy are a standing invitation to his jousting rejoinders, while pompous piety over matters of sex and religion arouses his cynical indignation and attracts sharp, withering rebuttals. His style is convivial and occasionally anecdotal — the aromatic air of a coffee shop conversation lingers deliciously over it — but there is a clear conclusion which reflects long and clear thinking presented logically and impassioned by the courage of conviction.

His columns dismiss the ideological claims of both Bolshevism and Chinese communism. In a defence of the ideological legitimacy of revisionism, which communists revile, he compares them with “all good ‘Bible-thumping’ fundamentalists” who have “an extraordinary litany of abuse for heresies and heretics”. Recalling the revisionism of the socialist Eduard Bernstein, de Cruz supports his critical approach to Marxism. Bernstein “heavily decried the Utopian element in communism — all the guff about heaven on earth being realised eventually under the communist system, when the state would wither away, and, as Lenin said, every cook could become Prime Minister and every Prime Minister could cook”. However, de Cruz's break with communism did not blind him to the opportunities being created in Asia by fundamental shifts such as the Sino–American rapprochement of the early 1970s, the Vietnam War, and consequently the prospects of the Association of Southeast Asian Nations (ASEAN). He took a keen interest in geopolitical and diplomatic trends that would influence the fortunes of Singapore. Thus, he sounds a discordant note in the midst of the general rejoicing over China having lifted the bamboo curtain to admit table-tennis players and journalists from America.