[10] The administration of George W. Bush decided in 2003 to engage in research towards a new generation of small nuclear weapons, especially "earth penetrators".

[11] The budget passed by the United States Congress in 2004 eliminated funding for some of this research including the "bunker-busting or earth-penetrating" weapons.

In 2014, Bulletin of the Atomic Scientists released a report, stating that there are a total of 2,530 warheads kept in reserve, and 2,120 actively deployed.

[18][19] The U.S. Air Force currently operates 400 Minuteman III ICBMs, located primarily in the northern Rocky Mountain states and the Dakotas.

In addition to this, the U.S. military can also deploy smaller tactical nuclear weapons either through cruise missiles or with conventional fighter-bombers.

Approximately 12 U.S. attack submarines were equipped to launch nuclear Tomahawk missiles, but these weapons were removed from service by 2013.

[20] The United States offensive biological weapons program was instigated by President Franklin Roosevelt and the U.S. Secretary of War in October 1941.

[25] In 1951, the US military also released fungal spores at the Norfolk Naval Supply Center on African-American workers to see if they are more susceptible to the pathogen than Caucasians.

[26] In 1966, the US government released Bacillus globigii on the New York Subway to research how a civilian population can be used to spread pathogens.

The Dugway Proving Ground facility in Utah, opened in 1942, to this day tests and stores biological weapons.

The 800,000 acre facility has reportedly weaponized fleas, mosquitoes, as well as conducted experiments on both animal and human subjects.

[27] A more advanced production facility was constructed in Pine Bluff, Arkansas, which began producing biological agents in 1954.

In 2001, negotiations ended when the Bush administration rejected an effort by other signatories to create a protocol for verification, arguing that it could be abused to interfere with legitimate biological research.

In 1943, German bombers attacked the port of Bari in Southern Italy, sinking several American ships – among them John Harvey, which was carrying mustard gas.

After the war, the U.S. both participated in arms control talks involving chemical weapons and continued to stockpile them, eventually exceeding 30,000 tons of material.

After the war, all of the former Allies pursued further research on the three new nerve agents developed by the Nazis: tabun, sarin, and soman.

Over the following decades, thousands of American military volunteers were exposed to chemical agents during Cold War testing programs, as well as in accidents.

[33]) The U.S. also investigated a wide range of possible nonlethal, psychobehavioral chemical incapacitating agents including psychedelic indoles such as LSD and marijuana derivatives, as well as several glycolate anticholinergics.

[34][35][36] In late 1969, President Richard Nixon unilaterally renounced the first use of chemical weapons (as well as all methods of biological warfare).

[37] He issued a unilateral decree halting production and transport of chemical weapons which remains in effect.

Stockpile reductions began in the 1980s, with the removal of some outdated munitions and destruction of the entire stock of BZ beginning in 1988.

In 1986, President Ronald Reagan began removal of the U.S. stockpile of chemical weapons from Germany[39] (see Operation Steel Box).