Is Puerto Rico Covered by NATO?

NATO, the North Atlantic Treaty Organization, is a military alliance formed in the aftermath of World War II. The core principle of NATO is enshrined in Article 5 of its founding treaty: an attack on one member is considered an attack on all. This principle has only been invoked once, by the United States after the 9/11 attacks.
NATO members contribute militarily, financially, and politically to ensure the collective security of the alliance. This includes joint military exercises, intelligence sharing, and standardized military equipment.

The organization was formed by 12 countries, including the United States, in 1949. 20 more nations have since joined, with Sweden as the most recent member. This is an alliance among the nations of Europe and North America.

Geography

In fact, the alliance is based on geography, as the name hints. Article 5 lays out the basic principle of collective defense:

Article 5

“The Parties agree that an armed attack against one or more of them in Europe or North America shall be considered an attack against them all and consequently they agree that, if such an armed attack occurs, each of them, in exercise of the right of individual or collective self-defence recognized by Article 51 of the Charter of the United Nations, will assist the Party or Parties so attacked by taking forthwith, individually and in concert with the other Parties, such action as it deems necessary, including the use of armed force, to restore and maintain the security of the North Atlantic area.”

Article 6 defines “North Atlantic area” more specifically:

Article 6

“For the purpose of Article 5, an armed attack on one or more of the Parties is deemed to include an armed attack:

• on the territory of any of the Parties in Europe or North America, on the Algerian Departments of France ², on the territory of Turkey or on the Islands under the jurisdiction of any of the Parties in the North Atlantic area north of the Tropic of Cancer;

• on the forces, vessels, or aircraft of any of the Parties, when in or over these territories or any other area in Europe in which occupation forces of any of the Parties were stationed on the date when the Treaty entered into force or the Mediterranean Sea or the North Atlantic area north of the Tropic of Cancer.”

Does that include Puerto Rico?

Frankly, nobody is currently asking this question. Congress is, however, debating whether Hawaii is covered by the terms of NATO. If Hawaii, which is south of the Tropic of Cancer, is not covered, then Puerto Rico also is not covered. Both Puerto Rico and Hawaii, as well as the U.S. Virgin Islands and Guam, are south of the Tropic of Cancer.

Literal meaning

The sentence that tells us is this one: “For the purpose of Article 5, an armed attack on one or more of the Parties is deemed to include an armed attack…on the Islands under the jurisdiction of any of the Parties in the North Atlantic area north of the Tropic of Cancer.”

One reading of this sentence would be that it refers to “islands which are under the jurisdiction of [any of the parties in the North Atlantic area which are north of the Topic of Cancer].” That is, islands under the jurisdiction of NATO members would be covered. Hawaii, Puerto Rico, and Martinique, for that matter, would all be covered.

The other possible reading is that it refers to “[islands under the jurisdiction of any of the parties in the North Atlantic area] which are north of the Topic of Cancer.” That is, those islands among the islands under the jurisdiction of NATO members which are themselves north of the Tropic of Cancer.

With no commas and no recording of how this was said, we cannot be certain which reading was intended.

A letter to Secretary of State Antony Blinken from a group of U.S. senators says, “When the Senate Foreign Relations Committee recommended the Senate ratify the North Atlantic Treaty in 1949, it was with the understanding that overseas territories would not be covered by Article 6.” While we were not able to view the document cited in support of this claim, a newspaper article from 1965 confirms it.

A technicality?

The same 1965 article quotes Douglas MacArthur, who was the Assistant Secretary of State at the time, as saying that this geographic concern was “a technicality.” He seems to have felt that an attack on Hawaii would probably not be an isolated incident which could be interpreted as not being an attack on the United States as a whole. Since Hawaii is now a state — which it was not in 1949 — it is a safe bet that the United States would feel threatened by a military attack on Hawaii.

There is also Article 4, which says that “The Parties will consult together whenever, in the opinion of any of them, the territorial integrity, political independence or security of any of the Parties is threatened.” That would probably include Hawaii and Puerto Rico as well.

The question came up in reference to the Falklands War in 1982, when Argentina attacked the Falklands Islands, which were a British territory. The UK did not attempt to invoke Article 5, so we do not know for sure how the allies would have responded, but there is general agreement that Article 5 would not be relevant, because the Falklands are south of the Tropic of Cancer.

In fact, the existence of southern territories belonging to many of the members of NATO ids one of the reasons that many observers think it is unlikely that Hawaii could be included. Martinique is a department of France just as Hawaii is a state of the U.S., and many more examples can be found. It would be difficult for NATO to make an exception for one without making exceptions for all — and essentially opening membership to the entire world.

Then what’s the answer?

While we would like to see this go to court, the answer is probably that Puerto Rico is not covered by NATO, and will not be, even after statehood.