Defense Secretary James N. Mattis is in Brussels, Oct. 3-4, for two days of meetings with his fellow defense ministers at NATO’s headquarters.
So what is NATO, and what does it do?
NATO stands for North Atlantic Treaty Organization. It was formed in 1949 to provide collective security against the threat posed by the Soviet Union.
The original members were Belgium, Canada, Denmark, France, Iceland, Italy, Luxembourg, the Netherlands, Norway, Portugal, the United Kingdom and the United States. Though the Soviet Union has long since fallen, the world has continued to be a dangerous place throughout the nearly seven decades since NATO was formed, and now 29 nations are members of the alliance.
To make it easier for so many countries to communicate, NATO has two official languages: English and French. This means that it also has two acronyms -- in French, NATO is OTAN, which stands for Organisation du Traité de l'Atlantique Nord.
One of the founding principles of NATO is Article 5 of its charter, which states that an armed attack on one member nation would be considered as an attack on all. The alliance invoked Article 5 for the first time in its history following the 9/11 attacks.
In addition to contributing to the war effort in Afghanistan, NATO member nations responded by helping the U.S. military with airspace defense and security over the United States and with maritime patrols in the Mediterranean Sea to guard against movement of weapons and terrorists.