Finland, which trains 20,000 conscripts a year, has 280,000 combat-ready troops. It has a further 600,00 reserve troops. Sweden has an army of 50,000 troops, taking the two countries’ combined total to more than 880,000.
The two countries confirmed they would be applying for NATO membership last week, in a show of defiance against Vladimir Putin.
They submitted formal letters of application earlier today.
Speaking about their application, NATO leader Jens Stoltenberg said: “I warmly welcome the requests by Finland and Sweden to join NATO.
“You are our closest partners.
“All allies agree on the importance of NATO enlargement.
“We all agree that we must stand together, and we all agree that this is an historic moment which we must seize. This is a good day.”
Announcing Sweden’s decision, Foreign Affairs Minister Ann Linde said: “Today the Swedish Social Democratic Party took a historic decision to say yes to apply for membership in the NATO defence alliance.
“The Russian invasion of Ukraine has deteriorated the security situation for Sweden and Europe as a whole.”
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But earlier this week Mr Niinistö hit back, saying that “joining NATO would not be against anyone.”
He said his response to Putin is: “You caused this. Look in the mirror.”
Mr Niinistö said Russia’s invasion of Ukraine and cyber-attacks on Finland and Sweden had “altered the security environment”.
But Putin warned the Finnish president that the Nordic country is making a “mistake”, claiming that Finland faces “no security threats”.
The move brings an end to both Sweden and Finland’s long-standing commitment to military non-alignment.
Sweden has pursued military neutrality for more than 200 years, while Finland has done so for 75.