The success of the armed forces in pre-screening out gays and bisexuals from the 1940s - 1981 remains in dispute, and during the Vietnam Conflict some heterosexuals would try to pretend to be gay in order to avoid the draft. However, a significant number of gay men and women did manage to avoid the pre-screening process and serve in the military, some with special distinction. For example, in the 1950s - 1960s the Navy medical doctor
Tom Dooley received national fame for his anti-Communist and humanitarian efforts in Vietnam. His homosexuality was something of an open secret in the Navy, but eventually he was forced to resign and the Navy conducted the first official study on sexual orientation and the Navy regulations and rules.
The 1957 report, titled
Report of the Board Appointed to Prepare and Submit Recommendations to the Secretary of the Navy for the Revision of Policies, Procedures and Directives Dealing With Homosexuals (aka the Crittenden Report)
found that gays were no more likely to be a security risk than heterosexuals and found there were no rational basis for excluding gays from the Navy, although it stopped short of recommending a change in the regulations because of society's social mores.
Beyond the official regulations,
gays were often the target of various types of harassment by their fellow heterosexual servicemen, designed to persuade them to resign from the military or turn themselves in to investigators. The most infamous type of such harassment was called a "blanket party" and involved several other service members during the night in the barracks, who first covered the face of the victim with a blanket and then committed assault, often quite severely and occasionally even fatally. The introduction of "Don't ask, don't tell" with the later amendment of "don't harass, don't pursue" has officially prohibited such behavior, but reports suggest that such harassment continues.
The degree of official and unofficial attempts to separate gays from the armed forces seems to be directly related to the personnel needs of the armed forces. Hence, during wartime, it has not been uncommon for the rules regarding homosexuality to be relaxed. Up until 1981 it was the policy of all branches of the armed forces to retain a homosexual, at their discretion, thus promoting the "queen for a day" rule which allowed a person accused of homosexuality to remain in the armed forces if they could successfully claim that their behavior was only a temporary occurrence. This especially became the case during the Vietnam War.