Why are Sweden and Finland not yet in Nato and does the alliance want them?

The North Atlantic Treaty Organisation is a defensive military alliance formed in 1949 by 12 countries including the US, UK and France to counter the threat of postwar Soviet Russian expansion in Europe.

Its common security guarantee is based on article 5 of the treaty, which states that an attack on one member is an attack on all and commits members to defend each other in the event of armed aggression.

Both considered that joining the alliance would represent an unnecessary provocation of Moscow, and so have long pursued policies of neutrality, and then non-alignment, to avoid antagonising a major regional power.

Essentially, many Finns and Swedes increasingly feel that joining Nato will help keep them safe when they face a plainly belligerent and unpredictable Russian leader. Polls show public support for Nato membership has trebled to about 75% in Finland and surged to about 60% in Sweden.

Nato membership would mean that for the first time Finland and Sweden would have security guarantees from nuclear states.

Swedish media have said a final government decision will be made on Monday, with a formal application for membership to be submitted shortly afterwards. Many analysts believe the two countries will apply simultaneously.