France performs nuclear test at Mururoa Atoll

France is one of the five nuclear-weapon states recognized by the Non-Proliferation Treaty (NPT) but is not known to possess or develop any chemical or biological weapons. France is the only member of the European Union to possess nuclear weapons. France was the fourth country to test a nuclear weapon, in 1960, and tested its first thermonuclear weapon in 1968. Charles de Gaulle was influential in the country's decision to develop both weapons and nuclear forces. France is also believed to have tested neutron bomb designs. The forces were developed in the late 1950s and 1960s to give France the ability to distance itself from NATO while still deterring the Soviet Union. France remains the only NATO member to not participate in its Nuclear Planning Group.