During the 1980s Gritz undertook a series of private trips into Southeast Asia, purportedly to locate United States prisoners of war which as part of the Vietnam War POW/MIA issue some believed were still being held by Laos and the Socialist Republic of Vietnam – e.g., at Nhommarath. Those missions were heavily publicized, controversial and widely decried as haphazard – for instance, as some commentators stated, few successful secret missions involve bringing to the border towns women openly marketing commemorative POW-rescue T-shirts.

In the book Inside Delta Force, CSM Eric L. Haney, a former Delta Force operator, claims that the unit was twice told to prepare for a mission involving the rescue of American POWs from Vietnam. However, both times the missions were scrubbed, according to Haney, when Gritz suddenly appeared in the spotlight, drawing too much attention to the issue and making the missions too difficult to accomplish.

In 1986, after a trip to Burma to interview drug kingpin Khun Sa regarding possible locations of U.S. POWs, Gritz returned from Burma with a videotaped interview of Khun Sa purporting to name several officials in the Reagan administration involved in narcotics trafficking in Southeast Asia. Among those named was Richard Armitage, who most recently served as Deputy Secretary of State duringGeorge W. Bush's first term as President. Gritz believed that those same officials were involved in a coverup of missing American POWs.

During this period Gritz established contacts with the Christic Institute, a progressive group which was then pursuing a lawsuit against the U.S. government over charges of drug trafficking in both Southeast Asia and Central America.

In 1989, Gritz established the Center For Action, which was active on a number of issues, mostly pertaining to conspiracy theories. Attempting to build bridges among conspiracy theorists and other activists of both the left and right, in 1990 he held a conference in Las Vegas, Nevada called "Freedom Call '90". Speakers at that conference included October surprise conspiracy researcher Barbara Honegger, Bill Davis of the Christic Institute, conspiracy theorist Eustace Mullins, and several others. This newfound interest in conspiracy theories proved to be as controversial as Gritz's earlier missions searching for POWs, especially after allegations surfaced of antisemitism directed at one of the speakers, Eustace Mullins.

In 1993, Gritz changed his emphasis again and began offering a course called SPIKE (Specially Prepared Individuals for Key Events), where those events oppose the New World Order, which taughtparamilitary and survivalist skills because he taught there would be a total sociopolitical and economic collapse in the U.S. He also established a community in Kamiah, Idaho (contiguous to the Nez Percéreservation) called Almost Heaven. Both of these proved to be even more controversial than his past activities, attracting charges from anti-racist watchdog groups that he was trying to build a community of Christian Patriot believers and train them in paramilitary skills for a showdown with the government.

Several times he used his influence and reputation in the Patriot community in attempts to negotiate conclusions between legal authorities and far-Middle activists. In August 1992, he intervened on behalf of Randy Weaver who, with his family, was holed up on his rural home in Ruby Ridge, Idaho, after U.S. Marshals attempted to arrest him on a weapons charge. The 11-day standoff, which resulted in the deaths of a U.S. Marshal and Weaver's son and wife, ended after Gritz convinced Weaver to leave his cabin and place his faith and trust in the court system. In 1996, he unsuccessfully attempted to negotiate a conclusion to the stand-off by the Montana Freemen, a group of Christian Patriot activists who were wanted on a collection of charges. After speaking with the "Freemen," he left in frustration, stating that they presented him with what he called "legal mumbo-jumbo" to support their claims, and cautioned others in the Patriot movement not to support them (the stand-off ended when the "Freemen" surrendered after 81 days).