As Sweden and Finland deliberate joining NATO, the two countries are seeking more clarity on how to bridge the gap between filing their applications and when the military alliance’s security guarantees would kick in with full membership.

While there is little sign that the two Nordic nations would struggle to secure acceptance, Russia has repeatedly warned both against joining the North Atlantic Treaty Organization and so they are concerned about potential aggression from Moscow if they formally signal their alignment with the western bloc.

Public backing for joining the North Atlantic Treaty Organization underwent a historic shift in both nations after Russia invaded Ukraine, and in Finland, almost half of all lawmakers now openly support an application.

As policymakers have gone on a diplomatic overdrive to remove any doubts about being welcomed by all members, they seek more certainty about near-term guarantees that they wouldn’t be left alone against Russia. NATO’s Article 5 mutual defense clause only applies to members.

“Finland’s concern over the gray zone between the membership application and full membership” is “quite well understood among NATO countries,” Foreign Minister Pekka Haavisto said on Thursday.

It could take between four months and a year for the 30 NATO members to ratify their applications, Haavisto said, signaling he’d been given indication countries would be willing to hurry the process.


Asked about their possible memberships, NATO Secretary-General Jens Stoltenberg said earlier this week that he expected all 30 allies would welcome them if they decided to apply. He said NATO “will find ways to also address the concerns” about the interim period.

Finland and Sweden already have some degree of collective security commitments through their membership of the European Union. Article 42.7 of the EU treaty states that if a member is the victim of armed aggression, other members have the obligation to aid them, but this doesn’t bind the U.S. in the way that their membership in NATO would.

NATO officials say they would welcome Finnish and Swedish membership and point to long and deep partnerships with the countries, including through regular joint military exercises with their armed forces.

Any membership bid from Sweden hinges on the ruling Social Democrats changing their stance, while Finns appear to have made up their minds to join and are putting together a parliamentary process designed to engage lawmakers from across the political spectrum.

A security-policy white paper due in Helsinki next week won’t contain a proposal for joining, but the government and president are prepared to submit an addendum on that “when the time is right” after they are satisfied lawmakers back the bid, Haavisto said.

“I think we will end the discussion before midsummer,” Prime Minister Sanna Marin told reporters on Friday, referring to a holiday that falls on June 25 this year. “We will have very careful discussions, but we will also not take any more time than we have to in this process, because the situation is of course very severe,” she said.

Sweden and Finland have for years worked closely with allies on military interoperability, on exercises, training and also meet NATO standards when it comes to political, democratic, civilian, control over the security institutions and the armed forces, Stoltenberg said.

“There are no other countries that are closer to NATO,” Stoltenberg said on Wednesday.