Though on a tight schedule, Guerrero decided to develop into a booklet his thesis on the raison d’être of martial law he put forward in his New York Times article. Romulo launched Today Began Yesterday in Manila in early September 1975 and was issued as a newspaper serial in late September in time for the anniversary of the proclamation of martial law. Retitled later as Why Martial Law?, Guerrero justified the imposition of martial law in the Philippines, which he hoped would bring about reforms, using Philippine history as a backdrop beginning with the Philippine Revolution against Spain until 1972 in the context of Muslim secessionism and the CPP-NPA-orchestrated communist revolution. “One must seek in Philippine history,” he noted, “the nature of these reforms, political as well as social, and the way to bring them about best suited to the traditions and character of the Filipinos.” His thesis was that martial law, with its vision of a “New Society”, was a long overdue recognition of Rizal's call for “social regeneration” and Mabini's exhortation on “internal revolution”, which led Quezon to promote “partyless democracy” in a society Senator Juan Sumulong called “farcical representative government” reigned by “feared and detested oligarchy”.

What should the “New Society” accomplish? As if to remind President Marcos, he stated it would: