Theodore Achilles kept a draft of the North Atlantic Treaty in the bottom drawer of his safe during secret talks at the Pentagon. He stated that he never showed the document to anyone except Jack Hickerson, who later became known as John D. Hickerson.
Twelve states signed the treaty in Washington, D.C., becoming the founding members of NATO on the 4th of April 1949. Prime Minister Paul-Henri Spaak represented Belgium while Ambassador Baron represented Luxembourg among the signatories.
Article 5 defines the casus foederis where an armed attack against one member becomes an attack against all. Each state assists by taking action deemed necessary including use of armed force and this article has been invoked only once following the September 11 attacks on the United States in 2001.
Article 6 limits mutual protection to territories in Europe, North America, Turkey, and islands north of the Tropic of Cancer. A clarification issued on the 22nd of October 1951 extended coverage to Greece and Turkey through Protocol to the North Atlantic Treaty.
The treaty came into force on the 24th of August 1949 after deposition of all signatory state ratifications. Article 11 required initial ratification through constitutional processes by Belgium, Canada, France, Luxembourg, Netherlands, United Kingdom, and United States.