what is a nuclear triad and why is it the ultimate deterrent?

The triad consists of nuclear missiles launched from land-based silos, submarines, and aircraft. Russia has all three weapon systems. In November, 2024, Russia officially adopted a new nuclear weapons doctrine. The new policy states that Russia could launch nuclear weapons in response to an attack on its territory by a non-nuclear-armed state backed by a nuclear-armed one. The updated Russian nuclear doctrine, establishing a framework for conditions under which Putin could order a strike from the world's biggest nuclear arsenal.