The Nuclear Posture Review specifically pointed to a Russian doctrine known as "escalate to de-escalate", in which Moscow would use or threaten to use smaller-yield nuclear weapons in a limited, conventional conflict in Europe in the belief that doing so would compel the United States and North Atlantic Treaty Organisation to back down. Previous administrations, both Republican and Democrat, have worked to reduce the threat of nuclear weapons, and this review breaks sharply from that bipartisan tradition.
The US readiness to use its nuclear arsenal against Russia pre-emptively is nothing but an "attempt to question [Moscow's] right for self-defense against an aggression in a situation that is critical for the very existence of the Russian state", the statement concluded. "I'm afraid this Nuclear Posture Review will be used by other countries to ignore calls for nuclear arms reduction, and in doing so leave the world less safe".
On Iran, the review said the main goal was to prevent Tehran from developing nuclear weapons.
Iranian Foreign Minister Mohammad Javad Zarif says the United States' newly-announced nuclear policy brings the world "closer to annihilation".
The review sought to back up Mattis on how the US nuclear deterrent would be channeled in confronting Russian Federation and China, which are now viewed under the strategy as the main security challenges to the USA, replacing terrorism. "The Russians have been fielding systems while we haven't, and our first new system won't be ready until 2026 or 2027".
"These policy changes seem preparatory to withdrawing from the Intermediate-Range Nuclear Forces (INF) Treaty of 1987".
Iran accused the United States on Sunday of threatening Russian Federation with new atomic weapons after Washington published a document outlining plans to expand its nuclear capabilities to deter others.
However, the nonpartisan Congressional Budget Office has put the cost of modernizing the nuclear triad of bombers, land-based missiles and submarines through 2040 at $1.2 trillion.
"Russia considers the United States and the North Atlantic Treaty Organisation (NATO) to be the principal threats to its contemporary geopolitical ambitions", the report said. Most of that money would go to new generations of bombers and new submarines, and a rebuilding of the land-based nuclear missile force that still dots giant fields across the West.
One of the most controversial elements of the new strategy is a section that declares that the United States might use nuclear weapons to respond to a devastating, but non-nuclear, attack on critical infrastructure - the power grid or cellphone networks, for example.
First, it would modify "a small number" of existing long-range ballistic missiles carried by Trident strategic submarines to fit them with smaller-yield nuclear warheads.
"Low-yield" weapons, commonly referred to those with a yield of less than 20 kilotons, are mostly made for tactical use, and now are mainly carried on strategic bombers with gravity bombs.
"Some in that room may think that we should just put our heads in the sand and ignore the threats that are being faced out there and just let Russian Federation and China and North Korea continue to do what they are doing", Wood told reporters outside the conference hall.