Article Five is a founding principle of the NATO military alliance, requiring allies to treat an attack against one as an attack against all.

Donald Trump is “totally committed” to Nato’s Article 5 clause, the military alliance’s secretary general has insisted, despite the US president saying the mutual defence pact was…

Article Five is a founding principle of the NATO military alliance, requiring allies to treat an attack against one as an attack against all.

Keir Starmer played down alarm about whether US stands by Article 5 of the military alliance after Mr Trump said the meaning 'depends on your definition'.

U.S. President Donald Trump confirmed his commitment Wednesday NATO's core mutual defense pact at under which an attack on any member is an attack on all, after earlier sparking…