power vacuum

— Fourth, knowing what I did of the policies and actions of Moscow and Peking, I was as sure as a man could be that if we did not live up to our commitment in Southeast Asia and elsewhere, they would move to exploit the disarray in the United States and in the alliances of the Free World. They might move independently or they might move together. But move they would — whether through nuclear blackmail, through subversion, with regular armed forces, or in some other manner. As nearly as one can be certain of anything, I knew they could not resist the opportunity to expand their control into the vacuum of power we would leave behind us.