Let us be honest with each other. The threat to marriage is not the gays. It is a lack of loving commitment - whether it is found in the form of neglect indifference cruelty or adultery to name just a few manifestations of the loveless desert in which too many marriages come to grief.
The Berlin Wall wasn't the only barrier to fall after the collapse of the Soviet Union and the end of the Cold War. Traditional barriers to the flow of money trade people and ideas also fell.