Analysis of information sources in references of the Wikipedia article "Traité de l'Atlantique nord" in French language version.
« NATO called its second emergency meeting on Ukraine in response to a request from Poland under Article 4 of the North Atlantic Treaty relating to threats to a member state's security and independence. »
« Linas Linkevicius, Lithuania's foreign minister, responded on Saturday by invoking Article 4 of the North Atlantic Treaty ... for only the fourth time in the alliance's history. »