Turkey is the last member of the group to approve Finland's application to join, but Sweden's future is still unclear.

After staying out of military alliances for decades, Finland and neighboring Sweden said they wanted to join NATO in May of last year. This was in response to Russia's invasion of Ukraine in February.

Turkey ratified Finland's bid on Thursday, making it the 30th member to do so. The Finns should be able to finish their membership in the next few days, while Sweden continues to face opposition.

Turkey's decision made Finland's President Sauli Niinisto tweet, "We look forward to having Sweden join us as soon as possible."

Here are five things you should know about the two countries' applications and why Sweden's is behind.

Turkey's president


Why did two Nordic countries do a U-turn in history?

Most Swedes and Finns have been in favor of their military neutrality policies for decades.

But Russia's invasion of Ukraine last year made people change their minds quickly.

The change was especially big in Finland, which has a border with Russia that is 1,300 km (800 miles) long.

Before the application, public support for joining NATO had stayed between 20 and 30 percent for 20 years. However, an AFP poll in February showed that 82 percent of people were happy with the decision to join the alliance.

In January, a poll in Sweden showed that 63 percent of Swedes wanted to join the bloc.

During the Cold War, Finland stayed neutral because Moscow promised not to invade if it did. After the Iron Curtain fell, Finland did not join any military alliance.

After the Napoleonic Wars in the 1800s, Sweden made neutrality its official policy. After the end of the Cold War, this policy was changed to one of military non-alignment.

Why does split entry happen?

At first, the Nordic countries were set on joining the alliance together, and they agreed to send in their applications at the same time.

Even though they were told they would be welcomed with "open arms," their applications were quickly rejected, mostly by NATO member Turkey.

All of the members of NATO must agree for a country to join the alliance.

In the middle of March, Turkish President Recep Tayyip Erdogan asked parliament to approve Finland's bid, but Sweden's bid was put off because of a lot of disagreements.

In the same way, Sweden's bid was put off until "later" when Hungary approved Finland's bid on March 27.

Hungary is holding up Sweden's entry into the EU because it is upset that Prime Minister Viktor Orban's policies have been criticized. But Hungary is likely to say yes to Sweden's bid if it sees Turkey moving in that direction.

Finland, on the other hand, chose to move forward, even if it meant leaving Sweden behind.

SOURCE: NEWS AGENCIES