Former Yugoslavia

Historically, the Former Socialist Federal Republic of Yugoslavia (SFRY) produced chemical weapons and pursued both nuclear weapons and ballistic missiles. However, none of the successor states (Bosnia and Herzegovina, Croatia, Kosovo, Montenegro, North Macedonia, Serbia, or Slovenia) have weapons of mass destruction or programs for their development.

See Former Yugoslavia's performance in

Region Europe and Eurasia

1940-1987 Intermittently pursued a nuclear weapons program

Ended its nuclear program in the 1960s, but restarted after India’s nuclear test in 1974

April 28, 1992 Yugoslavia officially broke up

Nuclear

Collaborated with Norway on nuclear research until the early 1960s
Transferred all remaining HEU to Russia by the end of 2010
All successor states have independently signed and ratified the NPT

Biological

No evidence of any attempts to establish an offensive biological weapons program
All successor states have independently acceded to the Biological Weapons Convention (BWC)

Missile

Allegedly collaborated with Libya and Iraq on various types of missile development
Serbia is the only successor state with its own ballistic missile program, including the K-15 Krajina and Jerina-1 short-range ballistic missiles (SRBMs)
Bosnia and Herzegovina, Croatia, Montenegro, North Macedonia, Serbia, and Slovenia are members of the Hague Code of Conduct Against Ballistic Missile Proliferation (HCOC)

Chemical

Produced a wide variety of chemical weapons and delivery systems prior to its breakup in 1991
All remaining production equipment and materials destroyed under the supervision of the OPCW in 2003
All successor states have independently acceded to the Chemical Weapons Convention (CWC)