The Pentagon's gay ban is not based on military necessity.

When President Bill Clinton attempted to lift the U.S. military's ban on gay and lesbian soldiers, Congress reacted by enacting a law that prohibits known homosexuals from serving in the U.S. armed forces. The official justification for the new policy is the unit cohesion rationale, the notion that if known gays and lesbians were allowed to serve, unit cohesion, performance, readiness and morale would decline. The thesis of this paper is that the evidence that advocates of discrimination invoke to support the plausibility of the unit cohesion rationale does not constitute scientifically valid data. This paper was delivered originally as a lecture at the Commonwealth Club of California and broadcast subsequently on National Public Radio.