Finland – which shares an 800-mile border with Russia – is set to join NATO after the country’s president and prime minister announced their support for being part of the US-led military alliance. United. The Kremlin said the move would pose a threat to Russia.
Here’s what you need to know about NATO and how it works:
NATO is a European and North American defense alliance that was created as the Cold War escalated and is headquartered in Brussels, Belgium. The purpose of the alliance was to protect Western European countries from the threat posed by the Soviet Union and to counter the spread of communism after World War II.
To remember: An armed attack against one or more of them in Europe or North America will be considered an attack against all of them. Article 5 of the North Atlantic Treaty ensures that the resources of the entire alliance can be used to protect any member country. This is crucial for many small countries that would be defenseless without their allies. Iceland, for example, does not have a standing army. Since the United States is the largest and most powerful member of NATO, any state in the alliance is effectively under the protection of the United States.
The alliance began with 12 founding countries, but over the decades that followed the alliance grew to include a total of 30 members.
In alphabetical order, these are: Albania, Belgium, Bulgaria, Canada, Croatia, Czech Republic, Denmark, Estonia, France, Germany, Greece, Hungary, Iceland, Italy, Latvia, Lithuania, Luxembourg, Montenegro, Netherlands, Macedonia North, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Turkey, United Kingdom and United States.
Ukraine is not a member of NATO, but has long hoped to join the alliance. This is a sore point for Russia, which views NATO as a threat and vehemently opposes it.
Amid ongoing tensions with the West, Russia has demanded ironclad guarantees that the alliance will not expand further east, particularly into Ukraine.
But the United States and NATO have resisted these demands. The alliance has always had an “open door policy”, which states that any European country ready and willing to take on the commitments and obligations of membership is welcome to apply for membership. Any decision to expand the alliance must be taken unanimously.
After the end of the Cold War, NATO made it clear that it would welcome eastward expansion, and in 1997 the Czech Republic, Hungary and Poland were invited to begin membership talks.
Since then, more than a dozen countries from the former Eastern bloc, including three former Soviet republics, have joined the alliance.
Read it full explainer on NATO here and see a map of its current members below: