Explanation

NPT stands for Non-Proliferation Treaty

NPT signed: 1968

not a member of the NPT:

• India,
• Israel,
• North Korea,
• Pakistan 
•  South Sudan 

members of the five NPT nuclear-weapon states:

• China
• France
  
• Russia
• The United States
• The United Kingdom

Languages:

• English
• Russian
  
• French
• Spanish
• Chinese

Parties: 190 (complete list)

Iran threatened to withdraw from the Treaty on the NPT