Secretary of State Marco Rubio says President Trump acted to stop Iran from reaching what he calls a "line of immunity," where Tehran could build up enough missiles, drones and other weapons to make military action against its nuclear program far more difficult.

Rubio argues that was Iran's broader strategy: strengthen its conventional arsenal, deter outside intervention and then move toward a potential nuclear breakout.

"That's what the President prevented," Rubio says. "He saved the world a tremendous amount of trouble."