Allies
An alliance of nations is called a coalition.
Nations formed alliance with other nations to become stronger either by contributing lots of nations together and to attack other nations.
this is formed by the United Nations
The two nations formed an alliance to defend each other in case of attack.
Other nations in Europe formed alliance with Spain
Allies
At first, Europe was full of alliances. the league of nations formed in ww1, and it kept on till ww2, but then another alliance formed. after the war that alliance became the UN, the most powerful alliance in history.
NATO was a military alliance formed by nations of Weston Europe and North America to counter expansion
an alliance syatem
NATO
The alliance system was created by Otto von Bismark, and later formed the alliances between the Central Powers and the Great Powers in WWI. Technically, it hasn't ended. The "League of Nations" was created by the Americans before WWII (though America didn't join it), and was another form of alliance. After WWII, there is now something called the "United Nations" which is also a form of alliance. -Sangel99
It was called the Triple Alliance.