Finland and Sweden are expected to submit their applications to join Nato in the coming days amid the escalation of the Ukraine conflict. 

The two countries have for decades held the belief that peace was best kept by not choosing sides, but Russia's actions in Ukraine have sorely tested the appeal of non-alignment for the Nordic nations.

While there is no set time frame, any accession process is expected to be pushed through far more quickly than previous applications.

Here are the steps that will need to be taken for Helsinki and Stockholm to become full Nato members. 

READ MORE

What is NATO and why is Russia worried?

Salt and water battery could wean millions off gas

The British historian loved in China

How do Finland and Sweden formally start the membership process?

Nato officials and diplomats say that ideally the two countries should submit their requests together - most likely as letters sent to Nato headquarters - to simplify the bureaucratic procedure.

Sweden's government plans to submit its application next week after a parliamentary debate on security, sources told Sweden's Expressen newspaper.  

The Finnish parliament will also debate membership on Monday, but a majority of lawmakers have already signaled their support.

Who decides if they can join?

All of Nato's members have to agree to the accession. Therefore, representatives of the 30 members will meet in Brussels to discuss, and most probably accept, the membership request.

Other Nato aspirants, such as Ukraine and Georgia, have been asked to carry out reforms before joining, but Nato considers Finland and Sweden to be successful democracies with militaries that meet their standards.

What happens during membership talks? 

First, the countries will have to commit to what is known informally as Nato's "marriage vows".

Officials from Helsinki and Stockholm would be questioned as to whether they would uphold Nato's collective defense pledge that an attack on one ally is an attack on all.

These talks will likely take place at Nato headquarters in Brussels, taking as little as one day for each country, depending on whether they accept the terms of Nato's founding Washington Treaty.

The two countries are already considered to "contribute to the security of the North Atlantic area," as the treaty demands.

They will also have to agree to pay their share towards Nato's budget, take part in the alliance's defense planning, and promise to protect the bloc's classified information.

READ MORE: Finland must apply to Nato 'without delay,' say Finnish leaders

Will Finland and Sweden immediately become Nato members?

No. The 30 allies would be likely to grant Finland and Sweden membership, but initially they will be given observer status at alliance meetings. 

This means they would not be covered by Nato's collective defense guarantee, where if one country is attacked, all members are obligated to respond.

When will they gain full Nato membership status?

While national governments may agree to Finland and Sweden's membership, first, all allied parliaments must ratify the decision. 

Depending on elections, summer recesses, and bureaucratic delays, this can take anywhere between four months to a year.

Finally, after the "deposition of the ratification" of all allies, both Finland and Sweden must also deposit their "instrument of accession" at the U.S. Department of State.

Then they will officially be Nato members.