The two Spanish enclaves are the only territory the alliance has on the African continent.
When the North Atlantic Treaty Organization (NATO) was founded back in 1949, member states, still reeling from World War II's devastation, decided to establish a core principle to guide the alliance in future conflicts and international crises: Article 5 of collective defence.
"The Parties agree that an armed attack against one or more of them shall be considered an attack against them all," the founding treaty reads.
In the following article, the text describes the alliance's territorial scope: Europe, North America, Turkey, the islands north of the Tropic of Cancer (such as the Canary Islands or the Azores), and even the Algerian departments of France, which no longer exist.
But for Spain, the treaty raises an additional question: Does collective defence apply to Ceuta and Melilla, the two Spanish enclaves in Africa?
The protection of the two isolated regions is a security imperative for Spain, which has been walking a delicate line with Morocco to control migration flows and prevent sudden arrivals.
Last month, a stampede at the Melilla-Morocco border left at least 23 dead migrants and prompted international condemnation against the repressive policies of local authorities.
Ahead of a NATO summit in Madrid, the debate over Article 5, Ceuta and Melilla gained traction across Spain and put pressure on Prime Minister Pedro Sánchez to deliver answers.
"While NATO is a defensive Alliance, no one should doubt our strength and resolve to defend every inch of Allied territory, preserve the sovereignty and territorial integrity of all Allies and prevail against any aggressor," says the new strategic concept, adopted in Madrid.
Although the strategy doesn't mention Ceuta and Melilla by name, the Spanish government welcomed the wording as a necessary assurance, arguing it makes clear the territory of each ally is defined by their constitutions.
"I think that's all that needs to be said," said Sánchez. "Ceuta and Melilla are Spain."
Watch the video above to find out more about Article 5, Ceuta and Melilla.