Wolf Blitzer asked if he thought Russia was a bigger foe than Iran, China or North Korea.
"I'm saying in terms of a geopolitical opponent, the nation which lines up with the world's worst actors," said Romney. "Of course the greatest threat that the world faces is a nuclear Iran and a nuclear North Korea is already troubling enough."
"But when these terrible actors pursue their course in the world and we go to the United Nations looking for ways to stop them; when [Syrian President Bashir al-] Assad for instance is murdering his own people we go to the United Nations and who is it that always stands up with the world's worst actors, it's always Russia, typically with China alongside," he continued. "And so in terms of a geopolitical foe, a nation that's on the Security Council ... and is of course is a massive nuclear power, Russia is the geopolitical foe."