Which of the following statement(s) is/are correct about ‘North Atlantic Treaty Organisation’?
1. It is an intergovernmental military alliance based on the ‘Washington Treaty’ signed in the year 1949.
2. The organisation works on a system of collective defence whereby its member states agree to mutual defence in response to an attack by a non-member external party.
3. The headquarters of NATO is located in Washington DC.
4. The Article 5 of the NATO Charter is the most used treaty provision whereby any member of the alliance invites the participation of all treaty members in its war against an external party.
Select the correct codes from below -