Formerly a longtime supporter of President Ferdinand Marcos, Soriano wrote an "open letter" published in Manila's Business Day newspaper on September 5, 1983.
He called for Marcos to resign in the wake of the assassination of opposition leader Benigno Aquino Jr. while in military custody and questioned the impartiality of the commission investigating the slaying.
[3] Soriano was appointed by President Corazon Aquino as her first National Security Director in October 1986, amid rumors of the coup plot which would be disclosed a month later.
[5] In September 1988, special prosecutor Raul Gonzalez revealed to the media the fund transfer involving checks by the International Precious Metal (IPM), the firm contracted to gold mining at Fort Santiago, which was supervised by Soriano.
[6] Despite calls by various groups for his resignation,[6] Soriano still served as the national security adviser until being replaced by Rafael Ileto in February 1989.