Finland officially joined NATO, becoming the 31st member of the security alliance.
North Macedonia officially joined NATO, becoming the 30th member of the military alliance.
The 70th anniversary of NATO was marked by a gathering in London of world leaders, followed by a reception by Elizabeth II at Buckingham Palace.
Montenegro became the 29th country to join NATO.
NATO accidentally bombed a refugee convoy in Kosovo, killing seventy-three.
The Czech Republic, Hungary, and Poland formally joined NATO.
Spain officially became the 16th member of NATO.
Riots broke out in Iceland when the Icelandic parliament decided to join NATO.