190 countries are states parties to the Treaty (March 2016). India, Israel, DPRK, Pakistan and South Sudan remain outside the Treaty.

1) Nuclear Non-Proliferation: to prevent the spread of nuclear weapons to anyone, except the "nuclear-weapon States" Under the NPT “nuclear-weapon States” is a term that refers to the countries that detonated a nuclear device before 1 January 1967, namely China, France, the Russian Federation, the United Kingdom, and the United States.
2) Nuclear Disarmament: each state party is to promote nuclear disarmament negotiations
3) Peaceful Uses of Nuclear Energy: promote cooperation for the purpose of the peaceful uses of nuclear energy

The Treaty stipulates that, (1) while affirming the “inalienable right” of states parties to use nuclear energy for peaceful purposes, (2) each nuclear-weapon and non-nuclear-weapon State has an obligation not to proliferate nuclear weapons, (3) the nuclear-weapon States are obligated to pursue negotiations in good faith on effective measures relating to nuclear disarmament, (4) and each non-nuclear-weapon State undertakes to accept the International Atomic Energy Agency (IAEA) safeguards for the purpose of verifying the peaceful use of nuclear energy.  These rights and obligations form the NPT regime.  To ensure the purpose and the provisions of the Treaty are being realized, article 8 paragraph 3 of the NPT stipulates that a conference of states parties will be held every five years to review the operation of the Treaty.

Key provisions: The NPT contains a preamble and 11 articles.
Article I: nuclear non-proliferation obligation of the nuclear-weapon States;
Article II: nuclear non-proliferation obligation of the non-nuclear-weapon States;
Article III: obligation of non-nuclear-weapon States to accept IAEA safeguards;
Article IV: rights of states parties to the peaceful uses of nuclear energy;
Article VI: obligation of nuclear-weapon States to pursue negotiations in good faith on effective measures relating to nuclear disarmament;
Article VIII.3: hold a conference every five years to review the operation of the Treaty;
Article IX.3: definition of a “nuclear-weapon State”.

The 2015 Review Conference of the Parties to the Treaty on the Non-Proliferation of Nuclear Weapons, held in New York from 27 April to 22 May and presided over by Ambassador Taous Feroukhi (Algeria), ended without the adoption of a consensus substantive outcome. After a successful 2010 Review Conference at which States parties agreed to a final document which included conclusions and recommendations for follow-on actions, including the implementation of the 1995 Resolution on the Middle East, the 2015 outcome constitutes a setback for the strengthened review process instituted to ensure accountability with respect to activities under the three pillars of the Treaty as part of the package in support of the indefinite extension of the Treaty in 1995.