Ukraine could potentially join NATO even if parts of its territory remained occupied by Russia, the alliance's former Secretary General Jens Stoltenberg said in an interview on Oct. 4. One of the main arguments against granting Ukraine membership at the current time is that NATO's Article 5 mutual defense clause would immediately draw the alliance into a direct war with Russia.

A scenario in which Ukraine becomes a member of NATO despite some of its territories remaining occupied is quite realistic. In Ukraine's case, there are ways to address the issue of applying the mutual defense clause,