NATO
Organizations
in wich Poland participates or participated

NATO

Abbreviation from North Atlantic Treaty Organisation (NATO).
In French: Organisation du Traité de l'Atlantique Nord (OTAN).
NATO is a military alliance established by the signing of the North Atlantic Treaty on 4 April 1949. Headquartered in Brussels, Belgium, the organisation establishes a system of collective security whereby its member states agree to mutual defense in response to an attack by any external party.
The NATO Maintenance and Supply Agency (NAMSA) is located in Luxembourg.

Members                                                                                                                                         NATO summit 2002
Since 1949: Belgium, Canada, Denmark, France, (1966 - 1993 only a member of the political structure), Iceland, (no standing army), Italy, Luxembourg, Netherlands, Norway, Portugal, United Kingdom, United States.
Since 1952: Greece (not participating from 1974 to 1980) and Turkey
Since 1955: German Federal Republic (East Germany in 1990)
Since 1982: Spain
Since 1999: Czech Republic, Hungary, Poland
Since 2004: Bulgaria, Estonia, Latvia, Lithuania, Romania, Slovakia, Slovenia.
Since 2009: Albania and Croatia
Since 2017: Montenegro
More information

Polonica stamps:

Albania 1999, 25 IV
Albania 2008, 12 IV
Albania 2012, 28 XI
Belgium 2016, 24 X
 Bulgaria 2001, 05 X
Bulgaria 2009, 30 III
Canada 1999, 21 IX
Guinea, Rep. 2014, 09 I
 Italy 2002, 28 V
Kosovo 2024, 12 VI
Luxembourg 2008, 30 IX
Northern Macedonia 2019, 04 IV
 Northern Macedonia 2024, 04 IV