Last Friday, for the second time in less than two weeks and only the ninth time in history, Article 4 of the North Atlantic Treaty—NATO’s founding document—was invoked. While it was Poland that ...

The North Atlantic Treaty Organization (Nato) is a military alliance that provides collective security for its members. It was founded in 1949 with 12 original members to counter Soviet influence ...

Three Russian military jets violated NATO member Estonia's airspace for 12 minutes in an "unprecedentedly brazen"incursion, the country's foreign ministry said Friday. Estonia is set to request ...

EXCLUSIVE: Recent Russian incursions into NATO airspace have sharpened divisions inside the alliance over how to respond, exposing both the strength and the limits of collective defense. Secretary ...

All 32 North Atlantic Treaty Organization members are projected to reach the alliance’s expectation of spending 2% of GDP on defence after receiving intense pressure from President Donald Trump to hit ...

For 80 years Europe considered its peace inviolate. Now, it can no longer be sure. The buzz phrase for a new age of uncertainty is the “gray zone” — a state in which nothing is black or white; neither ...

Authorities inspect a house damaged by debris from a Russian drone shot down in eastern Poland. Wojtek Radwanski/AFP via Getty Images A NAC meeting in itself isn’t unusual. Every NATO summit is a NAC ...