In 1968, Stubblebine was transferred to the staff of the Military Assistance Command, Vietnam and later was assigned to the 25th Infantry Division as its G-2 (intelligence officer).

Stubblebine was strongly influenced by Lieutenant Colonel Jim Channon's New Age-inspired First Earth Battalion Field Manual (1979).

[7] In addition to alleged security violations from uncleared civilian psychics working in Sensitive Compartmented Information Facilities (SCIFs), Stubblebine offended then-U.S. Army Chief of Staff General John Adams Wickham, Jr. by offering to perform a spoon-bending feat at a formal gala; Wickham, a devout Presbyterian, associated such phenomena with Satanism.

[8] Stubblebine's successor as the INSCOM commander was Major General Harry Soyster, who had a reputation as a much more conservative and conventional intelligence officer.

Stubblebine and Laibow established a nonprofit organization called "Natural Solutions Foundation" which disseminated conspiracy theories about vaccinations, pharmaceutical companies and genetically modified foods.

[12] According to Stubblebine, after analyzing the damage done to The Pentagon by the hijacked aircraft during the September 11 attacks, he concluded "(an) airplane did not make that hole".

[13][14] In 2009, Stubblebine said he believed the H1N1 swine flu was "a genetically engineered virus that is part of a World Health Organization-United Nations-United States scheme to sterilize untold numbers of people".