Article 5: NATO’s common defense pledge that stands in the way of Ukraine’s admission while at war

VILNIUS, Lithuania (AP) — Ukraine may have gotten support and vague assurances from NATO leaders in Vilnius this week, but ultimately it received no clear commitment that it will be joining the club any time soon. Instead, the alliance leaders said they were removing obstacles on Ukraine’s membership path so that it can join more quickly once the war with Russia is over. For many, that argument gives Russia’s president a pretext to prolong the war. But if Ukraine joins NATO in the middle of the war, then Russia is at war with the entire NATO alliance. At the core of this conundrum is Article 5 – NATO’s common defense guarantee under which an attack on one member is considered an attack on them all.