Teller was a staunch anti-communist and believed that a strong U.S. military and technological superiority were essential to deter Soviet aggression.

Teller became a prominent advocate for the Strategic Defense Initiative (SDI), also known as 'Star Wars,' a proposed missile defense system. He believed that advanced technologies could provide a shield against nuclear attack. He lobbied extensively for this cause.

In his later years, Teller became a strong proponent of nuclear energy as a clean and reliable source of power. He argued that nuclear energy could help reduce dependence on fossil fuels and mitigate climate change.