NATO just got hundreds of tanks, 62 fighter jets, and a whole lot of artillery after Finland joined the military alliance

• Finland, Russia's neighbors, became a member of the NATO military alliance on Tuesday.
• It brings hundreds of tanks, 62 fighter jets, and lots of artillery and soldiers with it.

Finland is now a member of NATO, giving the alliance a new military partner that has hundreds of tanks and jets, and a history of fighting Russia.

Finland officially became a member of the military alliance on Tuesday, strongly motivated by Russia's invasion of Ukraine. The move more than doubled Russia's direct border with NATO countries.

This proximity, and Finland's own history of fighting Russia, has been a big factor in how Finland has developed its military, and in the size of the arsenal that it now brings to the alliance.

That arsenal includes around 650 tanks, Reuters reported.

The International Institute for Strategic Studies said in its latest assessment that Finland has at least 800 armored vehicles, including 200 tanks.

It also has 107 combat-capable jets, according to the latest assessment by the IISS, including 62 fighter jets.

Finland claims to have what it calls "Western Europe's strongest artillery," made up of around 1,500 weapons that include 700 howitzers and cannon, 700 mortars and around 100 rocket launchers, according to Reuters.

The country has dozens of training aircraft and surveillance radars, at least 650 anti-aircraft missiles, an undisclosed number of drones, anti-aircraft cannon and tanks, multiple types of vessels for its navy, and lots of transport vehicles, along with other equipment, Reuters reported.

Finland is also currently boosting its weapons stocks, by adding more missiles, a new anti-aircraft system, and more drones, Reuters reported.

Every Finnish person aged between 18 and 60 is also liable for military service, as the country's constitution says that every citizen is obligated to participate in its national defence.

Finland says it trains around 21,000 new conscripts every year.

And the country has a wartime fighting reserve force of 280,000 soldiers, and almost 900,000 people that can be mobilized, according to Reuters.

Finland said even before it joined the alliance that its defense forces "already meet NATO's military criteria: we have a strong national defence of our own and are adapted with the armed forces of different NATO countries."

Finland becoming part of NATO is seen as a nightmare for Russia, which considers the alliance a key threat.

Russian President Vladimir Putin partly justified his invasion of Ukraine by saying that he wanted to stop NATO expanding eastwards, but instead his invasion prompted Finland to abandon decades of neutrality to seek NATO membership.

Alexander Stubb, Finland's former prime minister, told Axios that Russia's threats over it joining NATO can be dismissed due to the strength of Finland's military.

"When you have military like ours, you really don't have that much to worry about," he said. "And Russia knows that."