The United States 'Triad' of Nuclear Weapons

Washington, United States: The Pentagon vowed Friday to reform how it manages the US military's vast nuclear arsenal after government reviews found low morale among missile crews, manpower shortfalls and poor leadership.

Nuclear-armed submarines, intercontinental missiles and strategic bombers make up the US atomic "triad" created during the Cold War, with an annual budget of about $16 billion. Here are the main elements of the force:


Land-based missiles:

The United States has 450 Minuteman III intercontinental ballistic missiles in silos at three bases in Montana, North Dakota and Wyoming.

Each missile contains a warhead of 300 kilotons, equivalent to 300,000 tons of TNT, or 20 times more powerful than the atomic bomb dropped on Hiroshima.


Ballistic missile submarines:

The US Navy has 14 Ohio-class submarines, or SSBNs, armed with ballistic missiles. Each sub carries 24 Trident II missiles, and each missile can carry up to eight nuclear warheads, according to the Navy.

The firepower of each warhead is estimated at 100 to 450 kilotons.

The fleet of nuclear-powered Ohio-class submarines is due to be replaced around 2030 by a new generation of subs at an estimated cost of $350 billion.


Strategic bomber aircraft:

The military has two bombers designed to carry out a nuclear attack: the venerable B-52, which has been in service since the 1960s, and the B-2 stealth bomber with its distinctive flying wing design, designed to penetrate air defenses.

The United States has 78 B-52s at two bases. The planes also can carry Tomahawk missiles fitted with nuclear warheads ranging from five to 150 kilotons.

There are also 20 B-2 stealth bombers, which have been in service since 1989. The B-2s can be armed with two types of atomic bombs, one with a maximum yield of 340 kilotons and another with 1.2 megatons.

The Pentagon is pursuing plans to build a new long-range bomber to replace the B-52 and B-2 aircraft.

In total, the United States currently has 1,642 deployed warheads and 912 missile launchers and bomber aircraft, while Russia has 1,643 warheads and 911 launchers, according to the State Department. The START treaty signed with Russia imposes a ceiling of 1,550 warheads and 700 launchers for each country by 2018.